What should this week tell you?  Buy hitters, sell pitchers.  Of course, this broad prediction does not apply across the spectrum, but if you're looking for the hottest of the hot and want to avoid the coldest of the cold, especially among affordable players, then follow that mantra.  The evidence:

Bulls

Ian Stewart - 2B/3B - (Colorado Rockies):  This rookie is certainly making sure that he won't blow this opportunity.  After his first go-round with the Rockies ended in an easy demotion to the minors, Stewart has made the most of his second chance.  Stewart has been annihilating opposing pitching, slugging .641 and posting a 1.045 OPS in the last two weeks, including 15 RBI.  Stewart has vaulted himself into the definite "keeper" category for keeper leagues.

Jason Bay - OF - (Boston Red Sox):  Bay seems to like his new digs very much.  Since coming over to Boston in the big Manny Ramirez trade, Bay is hitting .343 with a .543 SLG and .940 OPS.  He has also given the Red Sox an element they didn't have with Manny; in 17 games, Bay has stolen three bases, which has helped him score more runs than games played (18 runs in 17 games).  

Jason Kubel - OF/DH - (Minnesota Twins):  Kubel has always had the hitting ability, but perhaps he needed a big pennant race to really stoke the fires.  Kubel has given Minnesota a legitimate power option outside of Justin Morneau, and he has turned it on especially of late.  In the last two weeks, Kubel is hitting .409 with a .727 SLG, cracking three HR and driving in 10 runs in that span.  If Denard Span can continue to get on base and Kubel can continue hitting for power, the top of the Twins' lineup looks very strong in the stretch run.

Runners-up Bulls:  Hideki Matsui - OF - (New York )Yankees; Roy Oswalt - SP - (Houston Astros)

Bears

Justin Duchscherer - SP - (Oakland Athletics):  Perhaps one of the biggest fantasy surprises before the All Star break, with a stellar 1.82 ERA and 0.87 WHIP, Duchscherer has been hit rather hard since his All-Star appearance.  Since the break, Duchscherer has a 4.91 ERA and 1.42 WHIP, and now comes word that he will miss a few starts with an injured hip.  This development is not a big surprise, considering that he has thrown 141.2 innings this year, but has never thrown more than 96.1 innings in his major league career.  Keep this in mind even when he comes back from his hip problem.

Fausto Carmona - SP - (Cleveland Indians):  Carmona, like his team, was expected to take the next step up and be one of the elite pitchers in the league.  Instead, he has regressed in a season full of inconsistency and injury.  Carmona started off very well despite walking what seemed like every other batter, but since coming back from injury, those walks have caught up to him.  His WHIP is a whopping 1.61 right now, and he isn't striking anyone out, so right now, he shouldn't be on anyone's fantasy roster either.

J.J. Hardy - SS - (Milwaukee Brewers):  Hardy was one of the hot waiver-wire pickups right before the All-Star break, as he hit .310 with a .970 OPS in June and a .317 AVG with a .956 OPS in July.  However, he has cooled off considerably, hitting only .209 with a .642 OPS in August.  That makes three out of five months, so far, in which Hardy has an OPS of .702 or lower.  Much like last year, his HR total makes him an attractive fantasy option, particularly in a year when SS are not hitting for much power, but his inconsistency can be maddening to his owners.

Runners-up Bears: Huston Street - RP - (Oakland Athletics); Justin Verlander - SP - (Detroit Tigers)