WASHINGTON — There is speculation injured Cubs starting pitcher Kerry Wood will end up as the team's closer. Wood concedes it may happen, way down the line.

"Maybe at the end of my career," Wood said. "But I think I have quite a few good innings left. I'm tired of all this speculation."

Speculation first popped up during the offseason, a notion both Wood and Cubs management quashed.

The current wave of guesswork is gaining steam because Wood has been battling injuries the past two seasons, so making him a closer would be less wear and tear on his arm. Plus, the Cubs don't exactly have a reliable closer at the moment.

Wood, who is nursing a right shoulder strain, is expected back in June at the earliest. The plan is to keep him in the rotation.

"It's never been talked about," Cubs general manager Jim Hendry said of Wood going to the bullpen. "It's a non-story."

Rehab report

Second baseman Todd Walker (left knee injury) went 0-for-3 with a walk and a strikeout in Triple-A Iowa's 6-2 loss to Salt Lake on Saturday night. It was his first game for the I-Cubs after spending two days in extended spring training.

Walker is hoping to be ready for the White Sox series starting Friday, but the Cubs will wait to see how he progresses, especially on defense.

Also in that game, relief pitcher Joe Borowski, who is recovering from a fractured right wrist, threw a scoreless inning with one walk. The Cubs want to see how he responds from back-to-back appearances before they bring him back to the parent club.

Ramirez backs off

Aramis Ramirez was scratched from Sunday's lineup against Washington because of lower back spasms. He was also out of Wednesday's game against the New York Mets with the same ailment.

"It's the same back spasm that never went away," Cubs manager Dusty Baker said. "It just came back. Hopefully he will get some treatment (today) and have him ready for Tuesday."

After today's off day, the Cubs play a two-game set at Pittsburgh on Tuesday and Wednesday.

Minor matters

Iowa's Darren Oliver had another rough outing Saturday, giving up six runs in six innings. The veteran, who recently signed a minor league deal, is 0-2 with a 16.20 ERA in two starts.

Class A Daytona's Sean Marshall pitched seven scoreless innings and struck out nine in a 3-1 loss to Lakeland. He did not get a decision.