It never looks good when a pitcher walks off the mound midway through an at-bat with an apparent injury. But Joel Hanrahan's description of what happened in the ninth inning Monday night made his strained right forearm seem even more ominous.

Facing the Twins' Josh Willingham after already allowing the tying solo homer on a chest-high fastball to Brian Dozier, Hanrahan traced the injury to a “pull” that he felt on a pitch that went to the backstop. After a few more pitches, Hanrahan thought the sensation had subsided, but after walking Willingham, he tried throwing to first base.

“I got to the point where I tried to make a pickoff to first, and the ball barely got there,” Hanrahan said. “I threw one more, and I just couldn’t take it anymore.”

Hanrahan will undergo an MRI exam Tuesday to determine the severity of the injury. But the Red Sox already are planning on life without both him and fellow closer Andrew Bailey, who went on the disabled list earlier in the day with inflammation in his right biceps. After Monday night’s 4-hour, 44-minute marathon, manager John Farrell met with GM Ben Cherington and other members of the front office to determine who will pitch the ninth inning if Bailey and Hanrahan are sidelined simultaneously.

“We’ve got a couple of guys out there that we feel confident they’ll be able to close out games,” Farrell said, not mentioning names, although veteran reliever Koji Uehara had 13 saves for the Baltimore Orioles in 2010 and may be the leading candidate.

On Monday night, the Sox leaned on long reliever Clayton Mortensen, who replaced Hanrahan and recorded the final out of the ninth inning before giving them two more scoreless innings. He threw 42 pitches and gained a measure of redemption after allowing the winning run Sunday in Texas.