"I don't know," he said of his timetable. "You know how an old man's body is. I'm supposed to come off the DL on the 28th, and if I do, I should need a game or two in a rehab stint. You want to be able to run first, because you don't want to go play, hurt yourself again and have it not count. You want to be 100 percent first."
Mora, who was bothered by the hamstring for most of Spring Training, said he aggravated the injury while in Texas. The veteran also said he didn't want to go on the disabled list but was convinced by a meeting with manager Dave Trembley, president of baseball operations Andy MacPhail and head athletic trainer Richie Bancells.
"It wasn't my idea," said Mora. "It was the general manager's idea, and he's the one that makes the decisions. He just told me he's going to put me on the DL and he did it. We met together -- me, the manager, the general manager and the trainers. All three agreed to put me on the DL, so now I have to get ready first."
Baltimore has turned to Ty Wigginton at third in Mora's absence. Mora, an All-Star, said he's not sure when he'd need to be able to run if he's able to come off the DL by the 28th. And although Trembley said he expects to have Mora by then, the third baseman said he just wants to get better.
"If I'm not going to be able to be 100 percent, why should I try to force it?" Mora asked. "They should use another guy here. I don't want to be selfish and play at 50 percent.
"I don't want to see a guy hit the ball into the gap and not be able to score. That's not me."
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.