Beckett: Won't throw until healthy

BOSTON -- Ailing Boston Red Sox pitcher Josh Beckett expressed frustration Sunday that his lower-back injury has forced him to slow down his rehab process and said he needs to be 100 percent before he picks up a baseball again.

The right-hander was scheduled to come off the 15-day disabled list on June 3, but that's unlikely given his recent setback.

"It's Groundhog Day right now," Beckett said before Sunday's game against the Kansas City Royals. "Just trying to get things better."

Red Sox manager Terry Francona had said last week that once Beckett was able to throw a side session it would be a good sign, but during Beckett's bullpen on Friday pitching coach John Farrell noticed inconsistencies in his delivery and shut him down so he wouldn't suffer further injury.

"The day before my side was pretty good," Beckett said. "It was limited activity, but it gives you that sense of everything's going to be OK and the next day you come in and obviously it's not."

The Red Sox will again gauge where Beckett is at on Tuesday before deciding how to proceed. Beckett had a similar injury in 2008. He dealt with the problem all season, which led to other injures, so the club does not want a repeat performance and will be cautious.

"I've had a couple of days like that where I felt good, one day being the day before my side," Beckett said. "Then I'll have two or three days where it feels different every day, but it gets worse, or stays the same. It's definitely a day-to-day thing. I've had two days where I was excited about the next day. Then you go out and throw a side and it doesn't go very well."

Joe McDonald covers the Red Sox and Bruins for ESPNBoston.com. Follow him on Twitter.