Fantasy baseball waivers and the acquisition of fantasy baseball free agents can make or break your season. Your fantasy baseball cheat sheets won't help you after spring training. If your team remains the same after opening day, you will have trouble competing in your rotisserie baseball league.

Do you need to replace your fantasy baseball busts? Which fantasy baseball players can you ignore? KFFL.com's Fantasy Baseball Diamond Market gives you fantasy baseball tips and insight to sort through the masses quickly.

Key

Middle infielders

Jeff Keppinger, 2B/3B/SS, Houston Astros

Mets need electricity

The Astros activated Keppinger (toe) and will likely plug him back in at the keystone regularly. He hit .285 with five dingers, 46 RBIs and four steals before hitting the DL.

Keppinger has little counting-category value, but his solid batting average skills and Houston's mild surge could make him slightly more valuable.

Shallow mixed: Pass

Deep mixed: Watch

NL-only: Acquire

Corner infielders

Chad Tracy, 1B/3B, Florida Marlins

Florida has started Tracy at the hot corner in their past five contests. He has six hits and three RBIs in 18 at-bats in that time. The Fish may mix and match often at third, but they haven't found anyone to hold it down since they traded Jorge Cantu. Tracy has batted .256 in 78 total at-bats between the Marlins and Chicago Cubs and is still a capable hitter.

Shallow mixed: Pass

Deep mixed: Pass

NL-only: Consider

Pitchers

Matt Lindstrom, RP, Houston Astros

Many dropped him when Lindstrom (back) landed on the DL; Houston activated him today. He was the club's closer but may have a difficult time wresting those duties from Brandon Lyon, who has been stellar in Lindstrom's absence.

Lindstrom saved 22 in 28 chances, with a 4.15 ERA and 1.64 WHIP, before he was deactivated. It's likely that his back pain played a huge role in his disastrous August. The right-hander changed a thing or two about his outside-the-office routine and feels good now.

Does Houston still consider Lindstrom their closer of the future? Are they inclined to let Lyon play out the string as closer and reassess? Will the pair split duties? If you need saves, don't wait for those answers.

Shallow mixed: Consider

Deep mixed: Acquire

NL-only: Acquire

Jenrry Mejia, SP, New York Mets

The Mets called up Mejia and will throw him this Saturday at the Chicago Cubs. The right-handed prospect spent 27 2/3 innings in the bullpen with the Mets earlier this season, compiling a 3.25 ERA, a 1.59 WHIP and a 1.13 K/BB. Of the batted balls against him, about two-thirds were grounders, too.

The Mets have been uncertain about his role all year, but now he'll start. His mid-90s heat with natural movement sets up his inconsistent but effective change and unpolished breaking ball. He issued 14 walks in 27 1/3 frames with Double-A Binghamton. But, in his lone start for Triple-A Buffalo, he went eight stanzas, yielding five hits, a run (on a homer) and a walk, while fanning nine. Plenty of potential here, but the edges are rough.

Shallow mixed: Pass

Deep mixed: Watch

NL-only: Acquire