"Very [encouraging]," Indians manager Terry Francona said. "Structurally, he's good. We have some information about what's causing the impingement, so it's good news. We'll give him five days no throwing and then he'll be re-evaluated."
There is no timetable for Perez's return to the Tribe's banged-up bullpen.
The Indians placed Perez -- an American League All-Star in each of the past two seasons -- on the 15-day disabled list prior to Monday's 4-2 loss to the Reds. The closer felt a pinch in his right shoulder on a 1-1 pitch to Boston's Jacoby Ellsbury during a ninth-inning meltdown on Sunday, when Cleveland suffered a 6-5 loss to the Red Sox in walk-off fashion.
Perez missed roughly a month in Spring Training due to a right shoulder strain, but recovered in time to make Cleveland's Opening Day roster. On May 12 in Detroit, the right-hander felt discomfort in his shoulder while warming up in the bullpen and was held out of a save situation. Perez indicated that he felt fine in the time leading up to his ill-fated pitch to Ellsbury.
"He was throwing 94 mph [against the Red Sox]," Francona said. "When a guys comes off the mound, you sort of have an obligation to get him checked out. I think we were hoping he'd be OK. We've just got to calm it down a little bit."
Francona noted Monday that setup man Vinnie Pestano would slide into the closer's role while Perez was sidelined. Sidearmer Joe Smith becomes the top candidate for the eighth-inning role with a variety of arms available for the seventh.
Perez has posted a 4.32 ERA and converted six saves in eight opportunities between his 17 appearances this season. In his last three outings, the closer labored to the tune of a 23.63 ERA, allowing seven runs on five hits with five walks and three strikeouts. Prior to that stretch, Perez had never allowed that many runs in three straight outings in his career.
Heading into this season, Perez had converted 98 saves in 110 chances over the 2010-12 seasons, ranking fifth in the Majors with a 89.1 percent success rate (minimum 50 save opportunities). His 98 saves in that span were also the fifth most in baseball.
The loss of Perez comes amidst a rough stretch for the Indians, who had lost six of their last seven games, entering Tuesday. Dating back to May 18, Cleveland's bullpen ranked last in the Majors with an 8.01 ERA. In that time period, the Tribe's typically strong relief corps had yielded 27 runs on 36 hits in 30 1/3 innings.
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.