The arrival of spring always compels baseball fans to look forward in anticipation of the season ahead. After a winter that saw the Padres (surprisingly) grab many of the headlines and the Cubs push past their prolonged rebuilding phase, it's finally time for the season to begin.

Yet following a winter of countless moves, some of the smaller details get easily glossed over. While big contracts like those handed out to Jon Lester and Max Scherzer earn most of the attention, many other significant moves are quickly forgotten. Any baseball season brings with it unheralded moves that end up looming large come September. With that in mind, here are four transactions from this offseason that have largely been forgotten but could have big impacts on the season ahead.

Jason Heyward

For some, the fact Jason Heyward is now a Cardinal might be easy to forget. After all, St. Louis swooped in for Heyward way back in mid-November, well before much of the offseason's activity got underway. The Cardinals sent right-hander Shelby Miller and pitching prospect Tyrell Jenkins to the Braves in exchange for Heyward and reliever Jordan Walden.

Although Heyward's power stagnated the past couple seasons in Atlanta, he is still only 25 years old and is an elite defensive outfielder. He has also shown strong on-base ability and some believe Heyward has the potential to develop more power, especially considering he was shoehorned into a leadoff role for the Braves.

The Cardinals, meanwhile, enter 2015 with a few more question marks than normal. Adam Wainwright is coming off a shaky second half, leading to some doubts over how much a heavy workload has affected his arm's health. Michael Wacha is coming off his own injury-plagued campaign, and Yadier Molina has also had problems staying on the field in recent seasons. St. Louis, in other words, could use another star player to help share the load with its aging core. Whether Heyward sticks around beyond this season is a different dilemma, but the young outfielder will be a huge addition to the Cardinals in 2015.

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Nelson Cruz

Nelson Cruz signed a four-year, $58 million deal with the Mariners just after Thanksgiving, cashing in on his 40-homer campaign in 2014. Whether Seattle was smart to commit four years to a 34-year-old corner outfielder with past hamstring problems is certainly a reasonable question. Still, Cruz should help an offense that finished tied for 11th in the AL in runs scored last season, even if Safeco Field has traditionally been a terrible fit for right-hander power hitters.

With Felix Hernandez in his prime and over $200 million still committed to Robinson Cano, the Mariners are built to win now. Cruz's performance at the plate this year will go a long way in determining whether Seattle can earn a playoff spot while playing in a tough AL West. It's easy to forget the Mariners managed to win 87 games last season. Their pitching certainly wasn't the problem, and if Cruz can help lift a flailing Seattle offense then he'll be exactly what the Mariners paid for.

Brandon McCarthy

Many observers raised their eyebrows when the Dodgers signed Brandon McCarthy to a four-year, $48 million contract in December. The right-hander has a long injury history, though he's stayed relatively healthy the past two seasons. He also pitched like an All-Star in 14 outings down the stretch for the Yankees in 2014 after escaping the homer-happy confines of Arizona. While he finished the season with a 4.05 ERA in 200 innings, his 3.55 FIP indicates McCarthy probably pitched better than that and could thrive in a friendlier home environment like Dodger Stadium.

More importantly for the Dodgers, McCarthy should help solidify the back of a rotation that gave the club little value last year. With Clayton Kershaw and Zack Greinke already on the staff, McCarthy just needs to give the Dodgers a chance to win every time he takes the mound. That would be an improvement on the performances of Josh Beckett and Dan Haren from last season, and an even bigger help for Los Angeles once October rolls around. If McCarthy pitches like he did at the end of 2014, the Dodgers will have one of the best starting rotations in baseball.

Melky Cabrera

Melky Cabrera is a tough nut to crack. He's likely never going to match the .346 batting average he managed through 113 games for the Giants in 2012 (before being suspended for PED use). But he's also much better than the .682 OPS he compiled for the Blue Jays during a disappointing 2013. Ultimately, Cabrera probably most closely resembles the player he was last season, when he batted .301/.351/.458 for Toronto in 621 plate appearances.

That's a pretty good player for the White Sox to add to what was a roughly league-average offense in 2014. Cabrera is expected to hit right in front of star first baseman Jose Abreu in Chicago's lineup, and his on-base ability will go a long way in determining how many runs Abreu drives in this season. A strong year from Cabrera could give the White Sox one of the AL's better offenses. However, a disappointing campaign from the 30-year-old could delay the club's march back up the AL Central standings for another year.