ST. PETERSBURG, FLA. – Michael Tonkin will complete one of the fastest rises through the Twins' minor league system when he reaches the major leagues, less than 13 months after pitching for low-Class A Beloit.

Tonkin's fourth step up the organizational ladder since June 20, 2012, might last only three days — or it could be more permanent. "This gives us a chance to see him up here, to get his feet wet," said Rob Antony, the Twins' assistant general manager. "If he performs, maybe he stays."

Tonkin will join the team Wednesday and be activated Thursday, when lefthanded reliever Caleb Thielbar returns to Minnesota to attend the funeral of his grandmother, who died last week. Thielbar will be placed on the three-day bereavement list, creating a chance for another rookie pitcher.

"This kid has got some kind of arm, and we're starting to see the benefits of it," Twins manager Ron Gardenhire said. "In spring training, we liked it. He throws really hard, with a powerful sinker. He's got elbows and arms all over the place."

Tonkin's fastball approaches 97 miles per hour, which fueled his rise through the system. After three consecutive seasons in Beloit, the 23-year-old former 30th-round pick in 2008 moved up to Fort Myers last June, then opened the 2013 season at Class AA New Britain. He was promoted to Class AAA Rochester early last month after striking out 30 batters in only 24 ⅓ innings. Tonkin has posted a 1.32 ERA at Rochester and saved five games.

"He's pitching the best, he's on the [40-man] roster — it's the easiest thing to bring him in and have him available for three days. And Sunday, we'll have to make a corresponding move to activate Thielbar," Antony said of the 6-7, 220-pound righthander. "It could be Tonkin, or we could make some other move."

Thielbar has been pitching though the grief of losing a family member, but said he had channeled that emotion into his work. "This is a good escape for me, being able to pitch," he said.

Lineup card mishaps

The wrong batter stepped into the on-deck circle — but never the batter's box — a couple of times during spring training, Gardenhire said. So he's empathetic to Giants manager Bruce Bochy, whose team was caught batting out of order last week.

"Believe me, that's a nightmare. We stare at this [lineup card], go over and over and over it," Gardenhire said. "And still, on certain days, we'll send one over [to the other manager before the game], and they'll go, 'You've got two guys playing center.' "

Gardenhire said he has collected kangaroo court fines from his coaches for missing typos and double-positions on the pregame lineup cards that both teams send each other a few hours before first pitch. But he and his staff are especially vigilant about the "official" cards that are exchanged at home plate before the game, since making a mistake on those can cost a team, as it did the Giants, who had a Buster Posey double wiped out in a game with the Dodgers last week.

"It's something we pay a lot of attention to," said Gardenhire, whose lineups frequently shuffle the bottom of the order. "We all read it over. But it's inevitable — we'll come back in and we've got three left fielders."

Etc.

• Josh Willingham has begun doing light exercises as he recovers from knee surgery, Antony said. But another outfielder, Wilkin Ramirez, "is not doing too great." Headaches and other symptoms of his May 22 concussion have returned, Antony said, "so basically, he'll take it easy and do very little until the symptoms subside."