By C. Trent Rosecrans
BEST MATCHUP: The day's early game has about as good of a pitching matchup as you could hope to see with Oakland's Trevor Cahill facing off against Boston's Josh Beckett. Chahill has struggled as of late, dropping his last three decisions after a 6-0 start, but he's still sporting a 2.31 ERA. Beckett is coming off his first loss since April 5, allowing more than a run for the only time in May in his outing against the Tigers, raising his ERA to 1.80. Not too shabby. Athletics at Red Sox, 1:10 p.m. ET (Watch live)
NL WEST SHOWDOWN: The Giants have just a half-game lead on the Diamondbacks, while the Rockies are 5.5 games back and in need of keeping within striking distance of the first-place Giants. The Rockies have the same record at home as they do on the road -- 13-15, something Giants starter Madison Bumgarner would love to say. San Francisco's lefty is 0-2 with a 5.49 ERA at AT&T Park. Colorado's Jhoulys Chacin allowed three first-inning runs against the Cardinals in his last outing, but settled down to allow just one more run in five more innings, helping save the teams' bullpen. He's 5-4 with a 3.33 ERA overall. Rockies at Giants, 4:10 p.m. ET (Watch live)
LEADERS MEET: In the only meeting between division leaders this weekend, the Rangers face a struggling Fausto Carmona. Carmona gave up nine runs in four innings in Toronto on Monday and has gone 0-3 with an 8.39 ERA in his last four starts. Carmona had a terrible outing on opening day before going on a seven-game stretch where he had an ERA of 2.22. He hasn't picked up a win in more than a month. Rangers starter Derek Holland has never faced the Indians. He's 4-1 with a 4.96 ERA, going 2-1 with a 3.41 ERA on the road. Rangers at Indians, 7:05 p.m. ET (Watch live)For more baseball news, rumors and analysis, follow @cbssportsmlb on Twitter or subscribe to the RSS feed.