Mark Prior, RHP, Rangers (Triple-A Oklahoma City)

It just seemed weird to write. Mark Prior, Rangers. Having not pitched in organized baseball since 2006, the former next big thing finally returned on Sunday, pitching a scoreless inning of relief while giving up two hits, a walk and striking out two. It wasn't an easy frame for Prior—he needed 28 pitches to generate his three outs — and on a stuff level, he's a shell of his former self, sitting at just 89-91 mph with his fastball while flashing a decent-at-best breaking ball. He could have easily walked away from the game and been set for life financially, but he had something to prove, if only to himself, and it's hard not to root for a guy like that.

Brandon Beachy, RHP, Braves (Triple-A Gwinnett)

It's likely that very few people would have picked Beachy to be the overall minor league ERA leader. Converted to starting at mid-season, Beachy needed some innings in his final start, and he got them, firing six scoreless frames on his 24th birthday with eight strikeouts to leave him with a 1.73 mark across Double- and Triple-A. Undrafted in 2008 out of tiny Indiana Weslyan, Beachy is not some kind of fluke, as he's a big athletic right-hander with a low-90s fastball—that's touched 94 mph at times— to go with a solid curve/change combination for secondary pitches. Not crazy stuff, but what makes him interesting is plus-plus command and control, as evidenced by his 48-to-6 strikeout to walk ratio in 45 2/3 Triple-A innings. He'll get a long look next spring, and might have to begin his big league career in a relief role, but plenty of scouts see a solid No. 4 or 5 starting job in his future.

Robinson Chirinos, C, Cubs (Triple-A Iowa)

Now in his 10th minor league season after signing with the Cubs out of Venezuela, Chirinos has gone from low-level journeyman to legitimate prospect since converting to catching in 2009. At 26, he's not especially old, and his offensive improvements have matched his advancements behind the plate. After putting up a .318/.412/.590 line for Double-A Tennessee, he didn't skip a beat in the Pacific Coast League, totaling six hits in his last three games to finish at .364/.435/.600 in 15 games. Finishing the year with a career-high 18 home runs in just 91 games, Chirinos has plus power for the position and his plus arm strength is finally showing up in games, as he gunned down 40% of opposing base stealers for Iowa. There's no room for him to start in Chicago, but he's a better backup option than Koyie Hill, and maybe an even better trade chip.

Brandon Guyer, OF, Cubs (Double-A Tennesee)

In the biggest offensive explosion of the second half, Guyer hit .415 in July, .402 in August and after going 7-for-11 in his last three games, he finished an even .500 (10-for-20) in September. When a 24-year-old college product who had never produced much in the stat columns suddenly puts up big numbers, the assumption is that he's probably one of those low-on-tools 4A types, but that's hardly the case with Guyer. A plus runner who stole 29 bases in 32 attempts, Guyer also has enough power to hit 15-20 home runs a year and he'll need it as so-so defensive skills limit him to a corner. It's not time to call him some big prospect, but he's certainly gone from organizational player to someone who deserves mention among the top outfielders in the system.

J.J. Hoover, RHP, Braves (Double-A Mississippi)

With the Braves' 2009 first-round pick already in the big leagues and high-ceiling arms like Julio Teheran generating plenty of attention, a pitcher like Hoover almost gets lost in the shuffle. A 10th-round pick in 2008 who signed for an above-average bonus of $400,000, Hoover moved up to Double-A at the end of the season and finished the year in style with a season-high 12 strikeouts on Monday in the M-Braves' season finale. A thickly-built righty, Hoover has seen his velocity jump this year, sitting in the 91-93 range while reaching back for 95 mph when he needs it. His power curveball has also shown marked improvement, and he's just some improvements in command and control away from really making some noise.

Anthony Rizzo, 1B, Red Sox (Double-A Portland)

Always a good hitter with projectable power, Rizzo shed that projectable label during the second half of the season, smacking two home runs over the holiday weekend to give him 25 on the year, more than doubling his previous season high. The power did come with a price, as Rizzo's batting average dropped significantly in 2010, but there is a line of thinking out there that after learning to hit for power, the next step is integrating the skill into an existing ability to hit for average. Lars Anderson got the big league call when Triple-A Pawtucket's season came to an end, but Rizzo has almost certainly passed him on the organization's first base depth chart.

Julio Rodriguez, RHP, Phillies (Low-A Lakewood)

When one talks about a pitcher being projectable, that's just saying he has a chance to find more velocity—it's certainly not any kind of guarantee. An eighth-round pick in 2008 out of Puerto Rico, Rodriguez was a pitcher to dream on when he signed. Six-foot-four, skinny and loose armed, Rodriguez sat in the upper 80s as an amateur, but he's slowly bumped that number up since turning pro, and the 20-year-old was among the top pitchers in the minors down the stretch, including a career-high 11 strikeouts over six two-hit innings in his final start. Now sitting in the low 90s with a number of 93- and 94-mph readings thrown in, Rodriguez has the ability to generate swings and misses with his heater, while his slow, loopy curveball projects as a second plus pitch down the road. With a 1.44 ERA in 56 1/3 Sally League innings and 90 strikeouts, Rodriguez has blossomed from projectable arm to a prospect with true big league projections from scouts.

Jean Segura, 2B, Angels (Low-A Cedar Rapids)

When Mike Trout moved up to the California League, the Angels' Low-A affiliate didn't miss a beat as Segura took over the leadoff role for the Kernels, while arguably taking over the title of most impressive position player in the league. Finishing the year 14-for-29 in a seven-game hitting streak, Segura led the Midwest League in hits while batting .313/.365/.464, and there is no weakness in his game. The 20-year-old Dominican has a solid approach to go with a lightning fast bat, gap power and plus-plus speed as evidenced by 50 stolen bases in 60 attempts. His development could go in a number of directions at this point—all of them good—but a likely scenario has him developing true 15-20 home run pop, while losing a step to become merely an above-average runner. Hampered by injury problems in the past, this is a true breakout year and Segura just might be the best prospect in baseball that nobody seems to talk about.

Justin Turner, INF, Mets (Triple-A Buffalo)

A seventh-round pick in 2006 already in his third organization, Turner is never going to generate an impressive scouting report. He's short and stocky, slow for an infielder and doesn't have much of an arm, but the Cal State Fullerton product is certainly, as clichéd as it sounds, a baseball player, and scouts adore his makeup and effort. The 25-year-old certainly ended the year with a bang, going 6-for-6 with a cycle on Monday, and his .333/.390/.516 line shows that he should certainly have some big league value, even as just a utility player.

Alex Wimmers, RHP, Twins (High-A Fort Myers)

In many ways, Wimmers is the perfect Twin, as he fits the mold of the kind of pitcher the organization has coveted and developed for years. He has average-to-plus velocity, but with outstanding command and a devastating changeup, he's the kind of arm who can move quickly and land in the middle of a big league rotation. With a career-high nine strikeouts in the last of his four professional starts, Wimmers limited Florida State League hitters to a .113 batting average while punching out 23 hitters in just 15 2/3 innings, and is on pace to start his first full season in Double-A.

A version of this story originally appeared on ESPN Insider Insider.