SEATTLE -- The run of misfortune continues for the Mariners' infield.

Although they reactivated second baseman Jose Lopez on Thursday, who missed seven games while on bereavement leave in Venezuela due to the passing of his sister, the Mariners placed starting shortstop Yuniesky Betancourt on the 15-day disabled list with a strained right hamstring suffered in Wednesday's game.

Betancourt strained the hamstring on his first step out of the batter's box while running out a grounder in the eighth inning of Seattle's 4-3 win over San Diego. He's hitting .250 this season with two home runs and 22 RBIs. Betancourt had been benched at times earlier this season for sloppy defense and impatience at the plate but had shown some signs of offensive life recently, raising his batting average by 18 points over the past seven games.

It's a lower hamstring strain and not the same injury he had in Spring Training, manager Don Wakamatsu said.

Even the guys the Mariners are bringing up from Triple-A are getting banged up. Chris Woodward would likely have been Betancourt's replacement at shortstop, but a groin pull will keep him out for at least another couple of games. Only a worst-case scenario would put him on the field, Wakamatsu said.

"I think it's more of an emergency type situation," Wakamatsu said. "He could play defense. The biggest thing is running that bothers him the most."

Ronny Cedeno got the start for the Mariners at shortstop on Thursday. Betancourt's injury also makes it all the more important that Seattle claimed infielder Josh Wilson off waivers on June 19.

"Good organizations, that's how you sustain or win championships, when you can cover these," Wakamatsu said. "We're awfully thin right now, and kudos to [Seattle GM] Jack [Zduriencik] for getting Wilson. If we didn't have Wilson at that point, I think we'd be awfully thin down there."