Yesterday we took at look some Yankees who are candidates to see their performances take a step back in 2012, and now it’s time to flip the coin and look at some players with the potential to improve. That’s the neat thing about the term “regress,” it can work both ways even though it’s somehow developed this negative connotation. The Yankees had a few players under-perform last year, some with good reason and others just because.

Boone Logan

On the surface, Logan had some killer stats last season. He struck out 9.94 batters per nine (24.9 K%) while walking 2.81 per nine (7.0 BB%) with a decent 42.4 GB%. Of course lefty specialists usually aren’t judged by their overall numbers, they’re on the roster to get left-handed batters out. That was a problem for Logan last year, who allowed same-side hitters to tag him for a .260/.328/.462 batting line in 118 plate appearances. He gave up three times as many extra-base hits to lefties as David Robertson despite facing 24 fewer hitters.

Logan’s strikeout (11.20 K/9 and 28.8 K%) and walk (2.30 BB/9 and 5.9 BB%) rates against southpaws were insanely good, but his problem was the long ball. His 40.6 GB% resulted in a 13.3% HR/FB ratio, though Hit Tracker says that three of the four homers he surrendered to lefties were Just Enoughs. That means they cleared the fence by less than ten vertical feet or landed less than one fence height beyond the wall. Two of the four homers would have remained in play in the other 29 parks according to their data. Just Enoughs are the most volatile type of homer given their definition, as they’re very prone to the weather and wind and ballpark. The homer issue may not be much of one, so if Boone can maintain those strikeout and walk rates, he should do just fine against left-handed batters going forward.

Russell Martin

We all know the story by now. Martin started last season ridiculously hot — .270/.367/.511 in his first 158 PA — before dragging himself across the finish line — .221/.303/.357 in his final 318 PA. The end result was a .237/.324/.408 batting line in 476 PA, or a .325 wOBA and a perfectly league average 100 wRC+. The average catcher produced a .309 wOBA and a 91 wRC+ last season, so Martin was an above average hitter relative to his position.

Like most players, Russ was a more productive hitter at Yankee Stadium (.345 wOBA and 114 wRC+) than on the road (.307 and 88). The easy answer is the short porch and more homers, but that’s not the case. Martin went deep eight times with a .175 ISO and a 15.4% HR/FB ratio at home last year, but clubbed ten homers with a .166 ISO and a 16.4% HR/FB ratio away from the Bronx. His walk and strikeout rates were essentially identical both home and away as was his batted ball profile, but his road batting average (.217 with a .220 BABIP) paled in comparison to his home rate (.260 and .288).

Martin is likely to see his home performance suffer a bit next year and his road performance improve a bit. In terms of process stats — the strikeouts, walks, batted ball types — he was the same hitter regardless of venue in 2011, he just got different results. Given the advantages of Yankee Stadium, the short porch and the fact that pretty much every hitter performs better at home, his home performance may not decline as much as his road performance improves. Martin will never be the guy he was in 2007 again, but a little more love on the road will boost his overall numbers and value to the team. Some more rest will only help further.

Nick Swisher

Swisher was basically the anti-Martin last year. He was dreadful to start the season — .206/.321/.288 in his first 193 PA — but a monster thereafter — .284/.397/.519 in his final 442 PA. Overall, Swisher finished with a .260/.374/.449 batting line (.358 wOBA and 122 wRC+), his worst performance as a Yankee and the second worst season full season of his career. His 23 homers were his fewest in five years thanks to the early-season slump.

Although he’ll never be a high-contact guy, Swisher has slightly improved his strikeout rate as his career has progressed while maintaining his high walk rate. He’ll never hit for a high average but that’s fine, he’s asked to provide power and patience. That power was missing early in the season, though his 14.3% HR/FB ratio in 2011 was right in line with his career average (14.9%). He just didn’t hit as many fly balls has he had in the past…

Swisher’s performance against right-handed pitchers last year was by far his worst as a Yankee, going from .375+ wOBAs to just .335. Again, it had to do with the lack of fly balls, a 41.4 GB% compared to 35.9% from 2004-2010. He’s still relatively young (turned 31 in November) and healthy, so there’s no reason we shouldn’t expect the fly balls to return in 2012. It’s not like we’re asking an injury-prone guy in his late-30’s to perform miracles here. More fly balls will lead to more homers, hopefully getting Swish back around 28-30 and making him more dangerous against northpaws.

Alex Rodriguez

It’s easy to forget just how stellar A-Rod was before his knee started giving him problems. He carried a .301/.377/.509 batting line (in 318 PA) into July before getting hurt, which is still excellent even if it’s not on par with his lofty standards. Alex was never the same after that (.191/.345/.353 in his final 84 PA), and the story is the same heading into 2012. I don’t want to spend too much time on this because I think everyone knows the deal. If healthy, A-Rod will produce big numbers even if they aren’t quite as big as they used to be. Whether or not he can actually stay on the field for 140 games or so is a total mystery, experimental knee procedures and new training methods be damned.

Rafael Soriano

Baseball’s highest paid setup man didn’t have a great first year in pinstripes, particularly early on. Most realized that his fly ball ways (just 35.2 GB% in 2011 and 31.4% career) were a bad fit for Yankee Stadium, so the big jump in homer rate (0.92 HR/9 and 8.3% HR/FB were nearly double his 2010 totals) wasn’t a surprise. What was a surprise was his walk rate, which jumped from 2.69 BB/9 and 7.5 BB% coming into the season to 4.12 and 10.0 in 2011, respectively.

Most of the walk damage came before Soriano hit the DL with an elbow problem. That makes sense, since elbow injuries have historically resulted in a loss of control while shoulder injuries have resulted in loss of velocity. Soriano walked 11 of 69 batters (15.9%) before hitting the DL but only seven of 95 batters (7.4%) after getting healthy. His strikeout (14.5 K% per-injury but 27.4 K% after) rate improved as well. Unfortunately, health is a going to remain a question going forward given his career-long battle with his elbow, but a healthy Soriano should be a very good reliever for the Yankees.

Mark Teixeira

Teixeira’s performance problems are all self-inflicted. He readily admits that he’s changed his left-handed swing over the last three years in an effort to take advantage of the short right field porch at Yankee Stadium, and says he’s working hard to correct the problem. He’s even talked about laying down bunts to beat the shift, which might be going a little too far. That’s another argument for another time.

With his massive power (.246 ISO and 17.1% HR/FB in 2011 vs. .250 ISO and 18.2% career), strong walk rate (11.1 BB% in 2011 vs. 11.5% career), relatively low strikeout rate (16.1 K% in 2011 vs. 17.2% career), and right-handed production (.410 wOBA vs. LHP in 2011 vs. .400 career) still intact, it’s all about Teixeira getting that batting average as a left-handed hitter (.224 in 2011) back up to his career norm (.277 coming into 2011). If he does that, his overall batting average (.248 in 2011) and OBP (.341) will also return to their previous levels (.286 and .377 coming into 2011, respectively).

Fixing the problem is much easier said than done. The uppercut Teixeira has added to his swing has resulted in a ton of fly balls (48.3% in each of the last two years) against righties, and fly balls will do a number on the ol’ BABIP (just .222 last year) since they’re generally easy to field. Eliminating the uppercut and returning to the level, all-fields approach that made him one of the game’s very best hitters will be tough because that’s a lot of muscle memory to undo. It won’t happen overnight, but it can be done. It will cost Teixeira some homers, but he’s a good enough hitter that he’ll be able to provide average, on-base skills, and 30+ homers at the same time. It doesn’t have to be one of the other.