PHOENIX -- With veteran right-hander Mike Timlin set to be activated for Saturday's game against the Diamondbacks, the Red Sox needed to vacate a roster spot. That left manager Terry Francona in the unenviable position of telling lefty reliever J.C. Romero that he had been designated for assignment just moments after Friday night's 10-3 victory over the Diamondbacks.

Romero had been one of the best lefty relievers in the game as recently as 2005, but struggled last year for the Angels and could never get into a rhythm with the Red Sox.

The Red Sox now have 10 days to release, trade or re-assign Romero, with the middle option seeming to be the likeliest.

"I know that [general manager] Theo [Epstein] talked to his agent," said Francona. "They're trying to make a trade to a place where J.C. can help. That was the move we had to make. That's not a fun way to celebrate a win."

Romero's final outing in a Boston uniform came on Monday night, when he managed to wiggle out of a bases-loaded, nobody-out jam in the bottom of the ninth inning at Oakland.

He struggled with his control, issuing 15 walks in 20 innings. Romero appeared in 23 games for Boston, going 1-0 with a 3.15 ERA.

However, fellow lefty Hideki Okajima has emerged into a big force out of the bullpen for Boston, and southpaw Javier Lopez has also been solid as a specialist, making Romero expendable.

"The emergence of Oki has been unbelievable," Francona said. "He's been a go-to guy. Because of that, then you couple him with Javy, sometimes you have to make very difficult decisions that aren't a lot of fun and that's' what we did."

The Red Sox signed Romero to a one-year, $1.67 million contract back in December.