"The MRI came back exactly the same as the previous one," Twins general manager Terry Ryan said Thursday. "He has a ligament strain, but there is no structural damage. That's the good news.
"Now we have to find out why he's having pain. We're not going to mess around with his future."
Ryan said the Twins will take an ultra-conservative approach with Liriano, who threw only 28 pitches Wednesday against Oakland in his first start in more than a month -- then walked off the mound, saying he heard a pop in his elbow.
Liriano, 12-3 with a 2.16 ERA, is done for the season, even if the Twins make the playoffs. Minnesota entered play Thursday leading the Chicago White Sox by 1½ games in the AL wild-card race and trailing first-place, idle Detroit by 1½ games in the AL Central.
"This had everybody a little flustered for a day, but we've been winning without him for a month," manager Ron Gardenhire said. "We've just got to go out and do the job."
Ryan said no surgery is planned, but he expressed caution that the prognosis could change.
"That's not a certainty, but that's what tests now show," he said. "Anything is possible.
"There's a lot of mystery as to why this happened in the first place. We want the doctors to figure out what the problem is and correct it."
Ryan refuted reports that the Twins rushed Liriano back in the heat of the race. The rookie went on the disabled list Aug. 8 and after a month of treatment, pitched three hitless innings Saturday in a rehab start for Triple-A Rochester.
"I don't think anybody anticipated what happened after watching him in Rochester," Ryan said. "We treated him with kid gloves and unfortunately there was a relapse. A lot of people thought it was his ankle or knee when he went out because we were so convinced his elbow was OK."
Gardenhire said rookie Matt Garza will take Liriano's spot in the rotation.
"We can just go with what we have," Gardenhire said. "If we are fortunate to get to the playoffs, I'm sure we'll have somebody out there throwing the ball over the plate and taking our best chance."
Ryan said giving Liriano the best chance to extend the promising start to his career is the Twins' immediate concern.
"I say let's get him ready for 2007 and that's tough for me to say today," Ryan said in reference to the playoff race.
"But I'd rather have him for 200-plus innings next year than for one playoff game.
"He's helped us get to this point. Now let's take care of him and not do anything foolish."