For Hughes, this marks his third stint -- within two weeks -- with the big league club. Mazzaro's contract had to be selected from Indianapolis, to where he had been outrighted after passing through waivers at the end of Spring Training.
Cumpton had another strong start in the nightcap of Thursday's doubleheader in Baltimore, but the Bucs needed his rotation spot for whoever will start Monday night against San Francisco. That decision has not yet been made, but it will likely come down to one of two lefties -- Jeff Locke or Wandy Rodriguez [right knee inflammation], eligible to come off the DL on Monday.
Pimentel has been used extremely sparingly, with six appearances despite having spent all of the season's first month in the Bucs' bullpen. He has allowed a run in four of his last five appearances.
Mazzaro was pretty close to perfect in six appearances with the Indians, going 1-0 with two saves and not allowing an earned run in 10 2/3 innings.
Hughes went 1-0 with four saves and a 0.00 ERA in six Triple-A appearances between two scoreless outings for the Bucs.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.