CHICAGO -- The Dodgers' latest roster manipulation, the placing of reliever George Sherrill on the 15-day disabled list Tuesday to make room for the activation of shortstop Rafael Furcal, came with the most unusual explanation of the year.

Sherrill was disabled with what was described as a stiff middle back suffered, he said, while getting into bed Saturday night.

Sherrill further said he's been healthy the entire season until this and that there are no physical ailments despite his 7.36 ERA.

Here's how Sherrill explained the injury:

"My wife was asleep Saturday night and I tried to get into bed softly and reached with my left arm and felt my back stiffen up. I felt it when I came in Sunday but felt I could pitch through it, but I feel it a little when I extend and finish my pitches. This is the safer thing to do."

Sherrill was asked if the injury had been pre-existing and was responsible for his poor pitching.

"No, no, no," he insisted. "It was just something that happened Saturday night. I'm able to play catch, but I still feel it."

Sherrill speculated his problems this year might be the result of pitching more innings last year than he has in previous years.

"I'm not making excuses because I've been pretty bad," he said. "I'm jut getting used to a short offseason and that could have something to do with it. Besides mechanics, everything seems to be fine physically."

"It may be a blessing," manager Joe Torre said. "He'll get a chance to get straightened out."

There had been speculation the club would place Nick Green on waivers to make room for Furcal. Green was called up from Triple-A Albuquerque when Furcal was disabled April 29.

But Chin-lung Hu, who has seen most of the action at shortstop for Albuquerque since Green was promoted, suffered a broken nose over the weekend, and management apparently wasn't willing to risk losing Green on waivers and be left without a suitable shortstop replacement should Furcal be injured again.

Sherrill, who was almost unhittable after his acquisition last summer, has been the opposite this season. He has compiled that 7.36 ERA in 22 games over 14 2/3 innings with 15 walks and 10 strikeouts. His last appearance before hitting the DL was Sunday.

The move leaves the Dodgers with 11 pitchers, and they are likely to need to add one by this weekend, when they need a fifth starter. Sherrill's only previous stint on the disabled list was in 2008 with left shoulder inflammation.

Furcal is returning from a strained left hamstring. Although he had a two-game Minor League rehab assignment and an extended spring game, Furcal said he has not tested the leg trying to steal a base. Last year, favoring his surgically repaired back, Furcal acknowledged he was afraid of stealing bases.