MINNEAPOLIS -- Matt Guerrier knew exactly what his job was on Thursday night: to try and help improve the Twins' chances for a victory on Friday night.

With Thursday's 7-3 loss to the Rays pretty much in hand by the time Guerrier took the mound with one out in the fifth inning, the Twins were looking to the reliever to make sure that no more arms had to be taxed in the defeat.

Guerrier was called upon after a rough start by Boof Bonser, who lasted just four-plus innings, and an injury to long reliever Brian Bass.

Most of which took place over the course of a difficult fifth inning.

"We had opportunities, but the game got away from us in the fifth," Twins manager Ron Gardenhire said. "We couldn't get away without giving up too many runs."

While Bonser admittedly didn't have his best stuff on Thursday, he still limited the Rays to just three runs, of which only two were earned thanks to a fielding error by right fielder Denard Span in the first.

It was when Bonser came out for the start of the fifth that things really got away from him in a hurry.

The right-hander gave up hits to the first three batters he faced, including a ball in the dirt that Carl Crawford swung at and somehow managed to tap into left field to drive in a run. Bonser then walked B.J. Upton to load the bases with no outs.

That's when Gardenhire came out of the dugout and motioned for Bass, the club's long reliever.

Having thrown just 72 pitches at that point, Bonser indicated that he was hoping for a chance to get out of his own jam. Instead, he exited having allowed six earned runs on seven hits while walking two and not striking out anyone.

"Obviously it was my worst one so far," Bonser said of his start. "But I definitely thought I could still stay in there longer."

Instead, the Twins turned to Bass who gave up a two-run single to Nathan Haynes. Bass then got Evan Longoria to strike out swinging on a sinker, but it was on that pitch when Bass felt his back tighten up.

After issuing an intentional walk to Eric Hinske to load the bases, Bass motioned to the Twins dugout for help and exited the game. He was diagnosed with a low back strain and is listed as day-to-day.

"It tightened up pretty good," Bass said. "In that situation, bases loaded, I'm not going to go out there less than 100 percent."

That meant that the Twins bullpen had to turn to Guerrier for an extended period of time. A task that the right-hander took and ran with, pitching 3 2/3 scoreless innings while allowing just three hits.

The outing for Guerrier came just three nights after he combined with Pat Neshek to blow a four-run eighth inning lead in Detroit. Guerrier said that he was trying to put forth a strong outing after such a disappointing one, but his main focus was making sure that other arms didn't have to be used.

"I was just trying to eat up innings so we can have a full 'pen [Friday]," Guerrier said. "As a long guy, that's what you try and do. You want to be out there as long as you can so everybody can be fresh tomorrow."

Neshek came in and threw one inning, but thanks to Guerrier's effort he was the only other reliever the Twins had to use.

Still, it meant that following the loss the Twins were without their two long relief options on hand for left-hander Francisco Liriano's second Major League start of the season. In his first start in Kansas City, Liriano lasted just 4 2/3 innings

Bass said that he didn't expect the injury to last long. He experienced a similar injury a few years ago in the Minors, and said that after some stretching and icing, he was able to get back pitching in about two days.

But while it may just be a few days for Bass to heal, Gardenhire seemed visibly concerned about the possibility of facing a game without a long relief option on Friday.

"We're a little short right now," Gardenhire said. "We used both of our long guys and one of them is hurt. We still haven't decided anything. I have to talk to the general manager."

No roster move was made after the game, so the Twins will likely have to rely on their other arms to carry the load if Liriano struggles early against the Indians.

"We've got a lot of guys down there," Guerrier said of the bullpen.

The hope for the Twins is that like Guerrier did on Thursday night, Liriano will make sure they don't have to use them.