Clearing the bases: Red-hot McDonald

First base: Pittsburgh's ace. The starting pitcher with the lowest ERA since April 18 isn't R.A. Dickey, but James McDonald, who threw his first career complete game on Thursday. McDonald lowered his season ERA to 2.19, and hasn't allowed more than three runs in any of his 14 starts. McDonald is only 6-3, a reflection of the Pirates' offensive problems (their .286 on-base percentage would be the third-lowest since divisional play began in 1969). In the seven starts where he's allowed one run or fewer and pitched at least six innings, McDonald is just 3-2. McDonald's curve continues to be a key pitch -- opponents are hitting just .102 against it.

Second base: Earning A's. A's pitchers have allowed just 22 hits over their past six games, setting a franchise record for fewest hits allowed over six games. The A's are 8-1 over their past nine games to claw within two games of .500. Ryan Cook continues to be a weapon out of the bullpen as he's allowed just two runs in 31.2 innings while holding batters to an .091 average. While it seems unlikely the A's can get back in the wild-card race, they are only 4.5 games out of the second spot -- although five teams are between them and the Rays, the current No. 2 wild-card team.

Third base: Oswalt's 2012 debut. Roy Oswalt makes his first start for the Rangers after getting ready with four starts in the minors, where he posted a 5.87 ERA. Despite Scott Feldman's struggles in eight starts -- 1-6 with a 6.43 ERA -- the Rangers' rotation has actually been quite productive as a group, with a 3.80 ERA that ranks third in the AL behind only the Angels and Rays. Oswalt, of course, has spent his entire career in the National League, so we'll see how he handles the switch in leagues. He gets the struggling Rockies in Arlington -- a park where he has a career 4.78 ERA in eight starts. Granted, that's been against some high-powered Rangers' offenses through the years.

Home plate: Tweet of the day. The Royals are only 4.5 games out of first place in the AL Central, and right when they're getting good news with the return of catcher Salvador Perez, comes the bad news that Felipe Paulino has been diagnosed with a torn ulnar collateral ligament in his elbow. He'll become the fourth Royals pitcher to have Tommy John surgery this year, joining Joakim Soria, Danny Duffy and Blake Wood. Man, talk about a franchise that just can't catch a break.