Third baseman Kevin Youkilis was out of the Red Sox lineup for the third consecutive game because of a strained lower back.

The Red Sox do not feel that Youkilis needs to go on the disabled list but they did put a patch on the roster on Tuesday, calling up Jose Iglesias from Triple A Pawtucket before a 5-3 loss against Oakland.

With rain coming down before the game, manager Bobby Valentine didn’t want to play the game with one less option on the bench.

“With the playing conditions and with the roster situation, didn’t think it was fair for the team to play so short in the infield,’’ he said. “So we have a backup in case we need it.’’

Righthander Junichi Tazawa was optioned to Pawtucket. He appeared in five games after being called up April 18, throwing 6 ⅓ scoreless innings. He was the only reliever on the team with options remaining.

Youkilis, 33, has been on the disabled list three times since the start of the 2010 season. A back injury was among his woes last season, making this latest injury a red flag.

He was not available Tuesday but was used as a decoy in the ninth inning, grabbing a bat and standing on the top step of the dugout.

Youkilis did not speak to the media, leaving Valentine to answer questions about his condition.

“I was with him today in the training room,’’ the manager said. “There are times when it’s pretty sore, different movements. He’s doing everything he can in the training room.’’

Youkilis was scratched from the lineup Sunday when he injured his back in the batting cage. He was scratched Monday when the irritation started during infield practice. On Tuesday, he never made the lineup.

“Other opinions or any of that stuff, I’m not sure where we are on it. It seems like he has a situation that we just have to get over,’’ Valentine said.

Making room