Phillies manager Ryne Sandberg explained that Diekman is the only left-hander in the Phillies' bullpen and had pitched five times in the team's first eight games. Sandberg wanted to keep his options open, but if Diekman had pitched the seventh inning and racked up eight to 10 more pitches he might not have been available to pitch Wednesday's series finale against the Mets at Citi Field, if they needed him.
The Phillies could use an extra left-hander in the bullpen. Left-hander Cesar Jimenez is in Triple-A after being designated for assignment Sunday to make room for right-hander Sean O'Sullivan on the 25-man roster.
"We don't have one to give them," Phillies general manager Ruben Amaro Jr. said. "The guys in the bullpen should be able to get righties and lefties out."
Jimenez is not eligible to be called up for at least another week. Left-hander Elvis Araujo is in Double-A and has posted an 8.10 ERA in two appearances. Left-hander Joely Rodriguez is starting for Triple-A and is 0-1 with a 6.00 ERA following two starts.
The Phillies had Rule 5 Draft pick Andy Oliver in Spring Training, but the left-hander struggled toward the end of camp with his command. He allowed six hits, five runs, 11 walks and struck out 12 in 12 2/3 innings.
Oliver cleared waivers and the Phillies outrighted him to Triple-A. But Oliver opted for free agency instead and signed a Minor League contract with the Rays.
Oliver would've been on the short list for a callup. "We offered him a pretty good deal to come back," Amaro said. "He just decided to go somewhere else. I think it was a very foolish move on his part, but that's OK. He had a choice. He had that right."
Todd Zolecki is a reporter for MLB.com. Read his Phillies blog The Zo Zone. Follow him on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.