Remember that the key to free agency is determining what player is going to have value down the line and picking up that player a week or more before his value changes. That is what is going to make your FAAB money last the most throughout the season, buying a playing for $4 the week before his value changes, compared to spending $250 on that same player once the manager announces his new role.

With almost a full month worth of stats in the book, here is a look at the fantasy baseball players who are rising or falling in value as of week four.

Rising:

C – Ryan Hanigan (Reds) – Hanigan has produced in limited at bats, with a .353 average and 10 RBI in 29 at bats. His counterpart Ramon Hernandez is hitting .250 in 40 at bats with zero home runs and four knocked in. We saw one change on Colorado already this week at catcher and another one may be coming in Cincinnati.

C – Max Ramirez / Matt Treanor – if you are looking for a catcher in the American League, you have these guys to pick from as the new catchers on the Texas Rangers roster. Jarrod Saltalamacchia came off the disabled list and was sent to Triple-A and Taylor Teagarden was optioned there as well.

C – Miguel Olivo – newly minted as the starting catcher in Colorado with Chris Ianetta being sent to Triple-A, Olivo is a good power play going forward. He is a hacker, striking out 36% of the time this season, so don’t expect his .300 batting average to last too long.

2B – Eric Young Jr. -recently called up by Colorado, it remains to be seen how much playing time he gets. With Clint Barmes struggling at second base, hitting .189 with a home run and seven RBI, a hot streak by Young could get him extended playing time. Young was off to a slow start in Triple-A, hitting .228 with three stolen bases at the time of his promotion.

3B – Mike Lowell – with David Oritz hitting .154 and striking out in 37%, Lowell is starting to see some more action. If nothing else, it boosts his trade for Boston by getting additional at bats and being able to perform.

OF – Austin Kearns - Kearns has been one of the few bright spots in the Cleveland Indians line up, hitting .386 with two home runs and 10 RBI in 44 at bats. With Matt LaPorta struggling, hitting only .211 with no home runs and one RBI in 57 at bats, the Indians are opting for Kearns to try to help generate offense for a team that is next to last in the American League in runs scored.

RP – Koji Uehara – currently on a rehab assignment in Double – A, Uehara has a chance to sneak into the closer role when he arrives back in Baltimore. Jim Johnson pitched the 8th inning in the last game with Alfredo Simon closing. The 28-year-old Simon was recently called up from Triple-A where he had a 1.59 ERA in 17 innings with 14 strikeouts.

Falling:

3B – Garrett Atkins – it always amazes me why professional sports teams don’t have a common sense executive on their staff. Someone that a general manager or manager would have to go to run by a trade or free agent signing and the common sense guy would approve the deal or say, no, that is just plain dumb. Which leads me to Garrett Atkins. Why the Baltimore Orioles thought he would be any better after not performing in Colorado’s hitter haven is beyond me. With a .220 batting average, no home runs and a paltry five RBI in 59 at bats, he is now relegated to bench duty in favor of Rhyne Hughes. Although Atkins might see some spot starts against left-handed pitching, he is basically worthless at this point.

RP - Chris Perez - Cleveland Indians manager Manny Acta is talking like Kerry Wood is going to come back as the closer when he returns to action in two weeks. Perez had the chance to lock down the job in Wood’s absence, and while he has saved four of five chance, his ERA of 4.05 and WHIP of 1.65 leaves something to be desired. If you own Perez and he does lose the job, he is still worth holding on to. Wood is no sure thing at closer, he could very well get injured again or traded at the deadline in the fall.

RP – Ryan Madson – Madson finds himself in the same position as Chris Perez. Filling in for injured closer Brad Lidge, Madson has failed to put a strangle hold on the role, with a 6.75 ERA and a 1.63 WHIP. Lidge is due back from the disabled list on Friday and will resume his role as closer. Again, just like Perez, Madson is still worth holding on to for the same reasons, outside of the trade possibility.

RP – Trevor Hoffman – before people panic about him losing it at age 42, he did have a somewhat similar start to his season in 2008 when he posted a 6.52 ERA and a 1.55 WHIP in April. That being said, it was interesting to note his lack of change ups thrown in his outing last night when he gave up five runs in the ninth inning against Pittsburgh. That has always been his money pitch and if he lost that for some reason, it could spell trouble. LaTroy Hawkins would be the handcuff but he has been knocked around as well to the tune of a 8.64 ERA. The best pitcher in Milwaukee’s bullpen so far has been Carlos Villanueva, who is unscored upon in 11 innings with 14 strikeouts.

SP – Jorge De La Rosa / Brett Anderson – both southpaw starters were placed on the disabled list this week and will miss anywhere from 4 to 6 weeks worth of action.