mlb.com

Mazzaro, 22, will be called up from Triple-A Sacramento to make his big league debut on Tuesday, and Oakland manager Bob Geren said it's not a "one-shot deal." Mazzaro, who was a non-roster invitee to his first Major League Spring Training this year, dominated in 10 Minor League outings, posting a 2.38 ERA in 10 games with the River Cats. With the exception of back-to-back starts, on April 20 and May 6, in which he allowed a total of 11 earned runs on 20 hits over nine innings, Mazzaro has been lights-out all year. In his other eight games, he's allowed zero or one earned run seven times and two runs once. Recently named the Pacific Coast League's top pitcher for a second successive week, Mazzaro scattered four hits and one walk while striking out six over six shutout innings in his most recent outing, and over his past four assignments, he's allowed one run on nine hits and four walks while striking out 21 over 27 2/3 innings for an ERA of 0.33.

The burly right-hander bounced back from a dreadful start during a 20-1 loss to Minnesota last Thursday with a stellar mound effort Tuesday night in Anaheim. Colon gave up Bobby Abreu's first home run of the season and three other hits over 6 2/3 innings, striking out three. More importantly, Colon didn't walk a hitter and let the defense behind him make one spectacular play after another, throwing 52 of his 83 pitches for strikes. Colon has a 6-4 career record against Oakland and has a 2-2 record with a 2.75 ERA over four starts at U.S. Cellular Field this season.