When managers leave Spring Training at the end of March, with a 25-man roster chosen, they intend to stick with it. For much of April, struggling players are given free passes; their team anticipates the player will come around in short order.

We are now beginning to enter the time of the year in which injuries and demotions start to pile on. Many minor league players saw a hot April up their prospect status, and are ready to thrive on a May opportunity. In the past few days, and in the coming few, there are six transactions that I want to highlight today. Which players will stick and which are merely Band-Aids?

We'll start things off with three players that have been called up to the Majors within the past three days...

Since August 1 of last season, Jose Contreras is the AL Cy Young: 14-1, 1.82 ERA, 2.77 K/BB. And while Freddy Garcia and Jon Garland came out of the April gates slow, Contreras established himself as the ace of the South Side. To many teams, his loss would be devastating. So why are White Sox fans simply shrugging off Conteras' sciatic nerve problems?

It isn't Brandon McCarthy. No, the young hurler labeled by many as the game's best sixth starter will remain in the bullpen while Contreras spends time on the DL. Instead, the White Sox brain trust chose to go with their seventh starter, 22 year old right-hander Charles Haeger.

Don't worry if the name doesn't ring any bells; before the season, Haeger was an afterthought in prospect circles. After a Spring Training that yielded a 10.45 ERA, his only notoriety came as a result of his knuckleball. Haeger will pitch against Ervin Santana and the LA Angels tonight, and thanks to six good starts, his current reputation is that of the minors' best knuckleballer.

In none of Haeger's six starts with the Charlotte Knights did he allow more than one run. Only once, in his last start, did he allow more hits than the number of innings he pitched. Conversely, Haeger will have to battle through control problems, having walked 20 batters in 40 AAA innings. And, as one might expect from a knuckeballer, the play of the catcher will be a focal point for Haeger's success. In his six starts this season, Haeger's catchers have allowed 14 passed balls, and Haeger has been credited with four wild pitches.

One can bet a healthy dose of walks, wild pitches and passed balls will not yield Contreras-esque success in Haeger's first Major League cup of coffee. If he does stymie the Angels, it will be because the knuckleballer provoked groundballs, few hard hits, and received help from behind the plate. Unfortunately for Haeger, trading for Doug Mirabelli is a luxury the White Sox cannot afford.

When the Yankees acquired Johnny Damon this winter, Bronx fans were convinced their days worrying about the outfield was over. Durability problems from Damon, Gary Sheffield and Hideki Matsui were hardly anticipated. The days of Bubba Crosby and Bernie Williams' weak arm were thought to be behind them.

Unexpectedly, Gary Sheffield now is on the DL, out with problems in his wrist. Rather than turning to Crosby or Williams, the Yankees recalled Melky Cabrera, the prospect that gave the Yankees a very forgettable cup of coffee in 2005. Cabrera's reputation had previously been tarnished in New York, but with early positive results from Columbus, the Yanks knew they had no better options.

As is his strength, Cabrera has magnificently kept his strikeout numbers down in 2006, whiffing just 9 times in 122 at-bats before his call-up. His contact skills should be a plus at any level, keeping his average at an acceptable level. His patience is decent enough; concerns have always focused on his power, or lack thereof. However, with 12 extra-base hits in his 31 International League games, some are wondering whether Cabrera could be more than a fourth outfielder.

The answer: doubtfully. Cabrera is a fine fill-in at the bottom of a fantastic lineup, capable of putting the ball in play consistently. But without any real strength to speak of, it's unlikely his power could ever support a full-time spot in a corner outfield spot. In center, his mediocre defense -- which looked poor in his first 2006 MLB game -- would be exposed.

In basketball, Cabrera would be a 6-6 power forward, or a 5-11 shooting guard; in other words, he's your classic tweener. Expect the Yankees to bear his play for the next two weeks, but don't expect him to be featured in any future plans besides trades or a bench spot.

Things weren't supposed to be this hard for the Angels. After committing to building the farm system, the Angels entered this season with the most top-heavy, ready farm system in the Major Leagues. But things haven't gone to plan in Los Angeles. Jeff Mathis didn't hit at all, Casey Kotchman's mono hindered his ceiling with the bat.

Now, Mathis finds himself in Salt Lake, Kotchman on the DL. The Angels have tried calling up Mike Napoli to fill in at catcher, and the short, powerful player would homer in his first Major League at-bat. Howie Kendrick was called up to fill in at a variety of roles, including at the DH spot instead of Tim Salmon. Sporadic play has proven to be the one thing that could slow Howie's play.

With Kotchman on the DL, the Angels decided to recall Dallas McPherson, another former blue-chip prospect that stagnated when reaching the Major League level. After failing to make the Angels out of Spring Training, McPherson showed his true colors in the Pacific Coast League, slugging and striking out. In his 102 at-bats, McPherson hit 20 XBH, while whiffing 49 times. Yes, in just 33 at-bats in 26 games did McPherson not slug an extra-base hit or strike out.

Concerns about McPherson's contact skills have never been more prevalent, his batting average ceiling appears to be at about .260. But for a team struggling to find offense, like the Angels have in 2006, waiting around for McPherson to hit the ball hard could actually present a welcome change.

Call-ups To Be

On Sunday, Cole Hamels had the worst start of his AAA career: he allowed a run. However, it was just one run in 7 innings, while allowing 5 hits and one walk. Hamels' ten strikeouts brought his AAA total to 36, amassed in just 23 innings.

Few prospects have flown up lists this spring like Hamels, whose polish appears ready for the Major Leagues. His change up, some have posited, could be among the best at the Major League level. Remember, you might, that Delmon Young once called the pitch the nastiest he had faced as a teenager.

With nine straight wins, the Phillies have continued to urge they have no need to rush Hamels. But, what Pat Gillick must understand is, at this point, it's not rushing. Hamels is ready. Ryan Madson is ready for a move back to the bullpen. It's a match made in heaven, and despite the loaded National League rookie crop, it's a move that could produce the NL Rookie of the Year.

Without a doubt, you have heard about Kerry Wood's first rehab start: 12 strikeouts in 5 innings. While the Lansing Lugnuts don't quite provide the intimidation that the Cardinals or Astros might, it's a start for Kid K, having spent so much of the last couple years on the DL.

When Wood returns, the Cubs rotation should return to being the club's strength. Carlos Zambrano and Greg Maddux are both dependable, fantastic starters. Sean Marshall has provided lightning in a bottle, seemingly improving in each of his six starts. Wood will make for a very good foursome, and it will be only weeks before Angel Guzman or Rich Hill is replaced by Mark Prior.

No matter how good the rotation might look, it appears that the Cubs simply don't have the offense to compete in baseball's (current) toughest division. In the Cubs last 11 games, they are 1-11, sliding near the bottom of the NL Central barrel. During this streak, the Cubs have scored a measly 13 runs, never more than three in any contest.

Kerry Wood's coming back? Yawn. Wake me when Derrek Lee returns.

Speaking of oft-injured pitchers, Ben Sheets is returning to the DL, leaving the Milwaukee Brewers again without an ace. Finally, it appears like the Brewers may have a competent replacement.

As good as Hamels has been in his short AAA stint, the best southpaw at the level in 2006 may be Dana Eveland, the David Wells look-a-like Brewer prospect. Yesterday, Eveland saw his first loss of a season come in a game in which Eveland did not allow an earned run. He was credited with two unearned runs, which he tends to allow as his groundball-provoking nature puts pressure on the seven behind him.

Dana Eveland isn't found often on prospect lists, his ceiling nowhere near as high as some prospects. He doesn't strike batters out at a good enough rate, more of a groundball-control specialist than anything else. But in a rotation currently featuring Tomo Ohka and an underachieving Doug Davis, Eveland could quickly become one of the Brewers best weapons.