Also see: Fantasy Baseball Diamond Market - Falling

Fantasy baseball waivers and the acquisition of fantasy baseball free agents can make or break a season. You may have adjusted your fantasy baseball cheat sheets over and over during spring training. If your team remains the same after opening day, though, you will probably have trouble competing in your rotisserie baseball league.

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

Key

Acquire - Add player (in most circumstances)

Watch - Track player; consider adding if trend continues

Pass - Do not add player (in most circumstances)

Third basemen

Joe Thurston, St. Louis Cardinals

St. Louis learned that the injury Mark DeRosa (wrist) suffered is a little more serious than they thought. The partially torn tendon sheath forced the club to place the prized trade acquisition on the disabled list, but he could still return shortly after the All-Star break. While DeRosa has been out, Thurston (.219-1-21, with three steals, in 201 at-bats) has been receiving most of the time at third base. He was a semi-regular there before DeRosa arrived, too, and he's merely a band-aid for the truly desperate.

Shallow mixed: Pass

Deep mixed: Pass

NL-only: Acquire

Outfielders

Gary Matthews Jr., Los Angeles Angels of Anaheim

Surprise! Vladimir Guerrero (knee) left last night's game with what the club called a strained muscle behind the knee. Manager Mike Scioscia doesn't sound terribly concerned, but does he ever? It may not be serious, but one can never be too cautious with Vlad or too early to take advantage of his situation.

Matthews (.228-2-22 in 145 at-bats) replaced Guerrero Tuesday and would likely to benefit most if the Impaler misses extended time. Matthews' numbers aren't pretty, but he is a solid contributor when he receives regular playing time. He collected 25 hits in 88 at-bats (.284) and scored 17 runs when Vlad was out of action earlier this year.

Shallow mixed: Watch

Deep mixed: Watch

AL-only: Acquire

Franklin Gutierrez, Seattle Mariners

The 26-year-old is in the midst of a 10-game hitting streak in which he has gone 20-for-40 (.500) with two dingers, seven ribbies and seven runs scored. Before his last hitless contest, Gutierrez was on a seven-gamer that yielded 10 hits in 29 at-bats (.345) with three bombs, five RBIs, seven runs and a steal.

His 2009 homer total (nine) has already exceeded last season's - in 138 fewer at-bats and despite moving to one of the least hitter-friendly parks in the league. He slugs better (.478) at Safeco Field than he does on the road. His flyball rate (35.0) isn't conducive to a large homer total, but Gutierrez is starting to deliver on the "developing power" promise. He's driving the ball more, so he may maintain that solid batting average (.295).

Shallow mixed: Watch

Deep mixed: Acquire

AL-only: Acquire

Clete Thomas, Detroit Tigers

Today Detroit called up Thomas, and manager Jim Leyland said the left-handed hitting outfielder will be in the lineup tonight. The skipper explained, "We're hoping to catch lightning in a bottle." That's because in his last 21 games with Triple-A Toledo, Thomas was hitting .357. The Tigers sent Thomas down in June so he could work on shortening his swing. Maybe it has paid off. It's not certain how often he'll be in there, but Leyland seeks a spark, and Thomas played nearly every day from early May through early June.

Shallow mixed: Pass

Deep mixed: Watch

AL-only: Acquire

Starting pitchers

Kyle Lohse, St. Louis Cardinals

Lohse (forearm) finished his rehab stint with a bang (two hits allowed over six scoreless frames) Tuesday at Triple-A Memphis. He's scheduled to pitch one end of the Cards' doubleheader Sunday at Wrigley Field. Lohse had a great April (1.97 ERA, 1.03 WHIP) but endured a rough May (6.85 ERA, 1.43 WHIP). He's no K artist, but he can be a solid matchup pitcher (3.20 ERA, 1.07 WHIP at home) for those who find his name on their league's free-agent list.

Shallow mixed: Watch

Deep mixed: Acquire

NL-only: Acquire

Manny Parra, Milwaukee Brewers

The Brewers are expected to call up Parra from Triple-A Nashville in time to start the club's game Thursday against the St. Louis Cardinals at Miller Park. As those who pegged him as a 2009 sleeper know, he was 3-8 with a 7.52 ERA and 1.92 WHIP; don't even look at his June splits. Milwaukee has few alternatives, though.

The southpaw walked a ridiculous 41 batters in his 64 2/3 major league innings this year. He didn't improve on that rate much with the Sounds (13 in 24 2/3 innings), but he held opponents to a .180 average, as opposed to his .311 mark against major leaguers. Well, that's why they're in the bigs. His .368 BABIP against should regress some because hitters weren't hitting him extremely hard; still, you should approach with extreme caution.

Shallow mixed: Pass

Deep mixed: Watch

NL-only: Acquire

Jonathan Sanchez, San Francisco Giants

Randy Johnson (shoulder) is on the disabled list, so Sanchez replaces the Big Unit - who has no timetable for a return - in the rotation. Sanchez will start at home Friday versus the San Diego Padres. His story is becoming old; he pitches stupendously in one outing but is then dreadful in the next. That's largely thanks to his maddening lack of control: 4.84 walks per nine lifetime, 5.94 this season.

The Friars usually present a good matchup, but SD has a solid road OPS. Encouraging sign: the lefty walked zero and fanned five in his four relief innings.

Shallow mixed: Pass

Deep mixed: Watch

NL-only: Acquire

Kevin Hart, Chicago Cubs

Just as three Cubs return from the disabled list, Ryan Dempster (toe) hits it. The right-hander may miss three or four weeks. Chicago sent Hart, who had been pitching out of the bullpen, down Monday, but he was recalled Tuesday to start today. If he pitches well, he may remain in the rotation until Dempster returns.

Hart, 27, isn't highly regarded, but he was 3-3 with a 3.10 ERA and 57 K's in 52 1/3 innings (six starts in 22 games) with Triple-A Iowa. He has allowed one earned run, on a solo homer, with a strikeout in his 5 2/3 big league relief innings. Walks appear to be a long-term problem for him.

Shallow mixed: Pass

Deep mixed: Pass

NL-only: Watch

Jeff Weaver, Los Angeles Dodgers

Eric Milton (back) returns to the DL for the same injury that put him there a month ago. Weaver fills in Saturday against the Milwaukee Brewers at Miller Park. The righty has been a valuable contributor (3.32 ERA); he's 2-0 with a 3.15 ERA in four games as a starter. He has been very composed. Milton has a big medical file, but it's unclear whether Weaver is considered a long-term solution. Think about taking a shot just in case.

Shallow mixed: Pass

Deep mixed: Watch

NL-only: Acquire

Also see: Fantasy Baseball Diamond Market - Falling