After five appearances as a reliever, Liriano returned to the rotation on May 30, and he's been the pitcher the Twins were hoping they'd see the whole season. Over his past six starts, Liriano has a 2.41 ERA and a Major League-high 40 strikeouts in 37 1/3 innings.
So the big question is: What has changed for Liriano since returning to the rotation?
If you ask around, you're likely to get a range of opinions, according to Twins general manager Terry Ryan.
"There's always those theories," Ryan said. "He was tipping his pitches, all that stuff. I've heard it all."
One recent theory is that Liriano is more relaxed on the mound because he's been chewing bubble gum during his starts. But Liriano, for one, isn't quite buying that one yet.
"I just started the last couple of starts," Liriano said. "I don't know why. I just started doing it. I don't think it makes a difference at all."
Ryan, though, said he's OK with Liriano sticking with chewing gum if it helps him stay on his current roll.
"Whatever it takes," Ryan joked. "If he needs bubble gum, I bet Bazooka will come in here with a boatload of bubble gum."
But one thing is for sure -- bubble gum or not -- Liriano does look more relaxed and more confident on the mound during his impressive stretch.
"I don't feel any pressure right now," Liriano said. "Before, starting the season, [I felt pressure] because in Spring Training, I was pitching so good. So I was thinking too much, trying to do too much. Now I'm just trying to go up there, relax, pitch the ballgame and enjoy myself."
Liriano has been going deeper into games, as he's pitched into the sixth inning during each of his past six outings, including against the White Sox on Monday, when he lasted a season-high seven frames. It's been a big change for Liriano, who pitched into the sixth inning just once in his first six starts, with his longest outing just 5 1/3 innings.
Liriano has been good in the early going all season -- he has a 1.50 ERA in the first innings of his starts -- but he's been able to keep it going deeper into games.
"All you had to do was watch that first inning and you thought, 'This guy's stuff is pretty crisp right now,'" Ryan said. "But if you go back a month ago, he'd throw an inning, but then by the second or third, it wouldn't last. But [Monday], we were watching and waiting, and there wasn't any give on him."
Part of that success comes from Liriano's improved command, as he's getting ahead of hitters and finishing them off with his slider or changeup. And as much as the strikeouts have been piling up for Liriano, he's not out there trying to overpower every hitter and looking for a strikeout in every situation, according to Twins manager Ron Gardenhire.
"Frankie's a strikeout pitcher, and we know that," Gardenhire said. "But when you get yourself in trouble, it's because you're trying to strike people out with your natural stuff. It starts with getting ahead by locating the fastball in and out, and he's starting to do that."
Staying composed has always been key for Liriano, who is prone to start overthrowing once he runs into trouble. But Drew Butera, who has caught all six of Liriano's most recent starts, says Liriano has done a better job of pitching with runners on base.
"For him, it's all about staying in control," Butera said. "When he gets out of whack and tries to throw pitches too hard or tries to do too much, that's when he starts throwing more balls."
Liriano, who can be a free agent after the season, remains a trade candidate for the Twins. But for now, they're just pleased that he's been a boost to a beleaguered rotation.
"We're seeing some really good fastballs, we're seeing some nice breaking balls and some nice changeups," Gardenhire said. "More than anything else, I think you're seeing a lot of pop on his fastball. It's really jumping out of his hand; he's in control out on the mound a lot better. And that's what we need."