Though it’s early in the season, there are already plenty of injuries affecting teams all over the majors. Figuring out how to patch up your roster without taking a hit in your stats is key to fielding a successful fantasy team. Today, we’ll take a look at some pitchers that may be available as free agents or via trade due to injuries or surprise starts, and why you will want to pick up or avoid them.

Randy Johnson‘s first start back in the majors could not have come at a better time, against the Giants and after the D’backs’ loss of Doug Davis. Although the Big Unit only threw five innings, he managed to rack up seven strikeouts without allowing an earned run. On the negative side, he did allow four walks, and three unearned runs did score. The important thing to watch for was how he pitched: how were his mechanics? Did it look like his back was causing him trouble? He had trouble locating his fastball throughout the game, but his velocity was fine, and his secondary pitches-especially his slider-were working for him. Johnson looked pretty good for a guy who hasn’t pitched in eight months thanks to back surgery, and even at age 44, he has the ability to dominate an opposing offense.

Many leagues have ignored Johnson because of the questions surrounding him; others who may lack faith in his staying healthy could deal him at a point when they feel his value is high. Even with the health risks, though, the upside is huge: Johnson could give you lots of strikeouts, plenty of wins while pitching on a legitimate contender, and, at the worst, passable ERA and WHIP numbers. Do yourself a favor and find a way to get Johnson on the cheap for your own club.

All in all, 2007 was a disappointing year for John Danks, who had issues with homers (1.8 per nine) that contributed to an overall 5.50 ERA. However much the Cell boosts home runs, 1.8 is awful lot of instant runs to be giving up, regardless of what stadium he calls home. His QuikERA-an ERA indicator based on strikeout, walk and ground-ball rates-was a more acceptable 4.85, certainly not too shabby for a 22-year-old. We can’t just pretend the home runs are not a problem though, especially because Danks had issues with them at the higher levels of the minors as well.

What Danks has done since to combat the problems is to develop a cutter. He worked on it last year as well, and has used it often in his starts this season. It’s a good pitch, and Danks has no issues employing it to get hitters out despite his limited time with it. It’s to be seen if the addition of this new pitch will help Danks become the pitcher some of his minor league numbers led us to believe he could be a few years ago, but it’s a start towards adjusting to major league hitters. I took the plunge on Danks last week before the Twins lit him up, but he recovered this week with 7 2/3 innings and no runs against the Athletics, while punching out four hitters and walking just a pair.

Danks is by no means an ace at 23, especially in his home park and in light of his home-run problems, but he’s a pitcher who could easily reverse his fortunes by inducing a few more ground-ball outs. Last year, 46 percent of his batted-balls were fly balls-and almost 14 percent of those fly balls were homers-but this year he’s managed to almost double his groundball/fly ball ratio from last year. Again, it’s too early to tell if this is legitimate progress, but it’s a trend that bears watching Danks is a pitcher capable of seven or more K/9, and that plus a few more grounders means that many fewer opportunities to give up bombs. Pick him up if he’s available, especially after last night’s start.

Todd Wellemeyer has some neat stats to start the year, with 20 strikeouts in 18 innings. His ERA of 4.00 isn’t optimal if you’re picky about rate stats and are aware that he probably won’t finish even there, but the strikeout rate and his decent K/BB of 2.9 have made up for it so far. The problem is that Wellemeyer’s already given up five big flies; I don’t expect him to give up homers on 36 percent of his fly balls on the season, but even when that figure falls out of orbit, there is the more serious issue of regression from even this level of performance to wonder about.

April is wonderful for player performance in limited playing time, and Wellemeyer’s line is no different. Yes, he has an ERA of 4.00, but he has also stranded 93 percent of his baserunners. He’s allowed 14 hits and seven walks on the season, with five of those hits coming as home runs. Even when the homer rate drops, his Left on Base rate should drop around 20 percent, to a more normal figure. His QERA is an improvement on his ERA, since it’s based on K/BB/GB rates, but even that should drop as the season drags on. His current K/9 is 10.0, but in his two longest campaigns, Wellemeyer posted K/9 of 6.2 and 6.8, respectively. Dropping his strikeout rate down to 2007 levels and plugging it into the QERA formula gives you 4.80. This is probably closer to his actual value-his Equivalent ERA from his PECOTA projection is also 4.80-assuming his problems with homers stop plaguing him. Wellemeyer doesn’t have much upside, and there are too many small sample issues surrounding his work so far. Unless you’re in a very large, very deep league, you can do better.

Cliff Lee may have barely snuck into the rotation in Cleveland this year, but he’s done his best to stay there in his two starts thus far, allowing only two runs in 14 2/3 innings pitched while also whiffing 12 batters and issuing a lone free pass. Home runs were Lee’s undoing in 2007, as he allowed 1.6 per nine, but this year he has yet to let a hitter go deep.

The problem with his performance is in his batted-ball data. Though Lee has shiny-looking peripherals out of the gate, a jump from the unusually low five percent liner rate he’s allowing now to a more normal 18-20 percent-right around his career and the league averages-will adversely affect the number of base hits he allows. The Indians‘ defense is solid, but it’s not so good that Cliff Lee’s .170 BABIP is a realistic indication of how he’ll do over the full season.

The good news is that Lee is handling his homer and walk issues well. Even when the liner rate and BABIP align, if his peripherals improve from ’07, then the Indians may have something more like the 2005-2006 era Lee on their hands. That’s a pitcher you can live with on your fantasy team, so you should acquire him for wins and half-decent peripherals, because the Indians are a legitimate contender.

In contrast to the guys we’ve already covered, Roy Oswalt is a high-profile pitcher giving fantasy owners fits with his poor start to the season. In three starts, Oswalt has lasted just 16 innings while giving up five homers after only allowing 14 all of last year. He has not seen a dip in his strikeout rates so far, and his walk rate has been fine, though that may be due more to how hittable he has been rather than superior control. Oswalt’s current BABIP is .430, which looks to be at least partially the defense’s fault. Oswalt’s liner rate is just around 21 percent, so you would expect his BABIP to be around the .330 mark, rather than 100 points higher. So what’s the problem? Houston is currently tied for 27th in Defensive Efficiency at .678 after ranking 17th at .692 last season, evidence that some of Oswalt’s BABIP boost is due to the poorer defense he’s relying on.

As for the rest, it’s not as cut and dried as it may seem. Last year, Oswalt’s BABIP was .318, not too far above his career rate of .311. The issue with this was his liner rate of 16 percent; with that line-drive percentage, his expected BABIP is closer to .280. While that may seem like good news for Oswalt, it isn’t, because his career liner rate is closer to 21 percent. You can anticipate his being closer to that level than last year’s fluke figure, which would put him right about where he was in the BABIP department last year anyways. Throw in the defensive problems, and Oswalt takes a hit in value.

To make the picture perhaps just that much more grim, Oswalt’s showing a few early problems according to Pitch f/x, courtesy of Dan Fox:

Roy Oswalt 2007

Roy Oswalt 2008

Now, obviously there’s not a ton of data to work with yet, as Oswalt has just three starts, but you can see that there are some problems with his fastball. Last year, his fastball averaged 93.2 mph and tailed 5.4 inches, while this season it’s averaging 92 mph and is tailing 4.8 inches. It’s a slight difference, but it’s enough that hitters aren’t swinging and missing as often-only two percent this year versus nine percent last season-and they are instead fouling off more pitches and putting others in play. Oswalt is also not throwing his curveball as much this season, though the data shows that there isn’t an issue with its movement.

It remains to be seen whether Oswalt’s dip in his velocity and movement is due to a mechanical problem, or if he’s just lost a little bit on his fastball now that he’s on the wrong side of 30. If you think it’s something he can fix, you should explore dealing for him on the cheap, but I’m not yet convinced the Astros and Oswalt bring enough positives to the table this year to merit the transaction.