The three players optioned to Indianapolis were right-hander Phil Irwin and infielders Chris McGuiness and Brent Morel.
Irwin was extremely sharp in two outings, allowing only one hit in three innings, but got a late start after dealing with elbow discomfort for a couple of weeks. The 27-year-old right-hander got the Pirates' first call last season when an emergency starter was needed, and will again be in that mix.
"He's throwing the ball very well," general manager Neal Huntington said, "we're just running out of innings. This will keep him on the right track to be able to help us at some point this summer."
Plans are for Morel to primarily play third base, his standard position, for the Indians. But the Pirates also want him to get comfortable at other infield positions, with the possibility of filling a super utility role.
"He'll also get some work at first," Huntington said, "and we're still intrigued by the thought he may be able to play second base. He'll get some pregame work there. He could add depth at a number of spots."
Not including among the 42 players in Major League camp (22 pitchers, four catchers, nine infielders and seven outfielders) is catcher Chris Stewart, who is expected to start the season on the disabled list after undergoing surgery on his right knee Wednesday.
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. Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak. This story was not subject to the approval of Major League Baseball or its clubs.