DETROIT – The Twins aren't ready to say Samuel Deduno will start Thursday's game against the White Sox. Then again, he might.

"We're talking about it. We've been kicking around some ideas," assistant General Manager Rob Antony said Sunday, a day after Deduno gave up seven runs over 2 ⅓ innings, raising his ERA as a starter to 6.52.

Antony said manager Ron Gardenhire and pitching coach Rick Anderson had discussed some mechanical problems that are hampering Deduno, problems that disappear during his between-start bullpen sessions but reappear on the mound. "Andy has some suggestions, so we're still working with him," Antony said.

"His last bullpen session was lights out. He got everything straightened out," Gardenhire said, but then allowed five consecutive hitters reach in Saturday's game, including a pair of home runs. "He has his good innings and his bad innings, and we just want to find consistency more than anything else. The last couple have been not very consistent, so everything is out there — we're trying to figure out the best way to go about it. How can we get him better, that's what we're looking for now."

So will Deduno make his next start on Thursday? "Absolutely," Gardenhire said, before hedging — "as of now."

"We'll see," agreed Antony, who acknowledged that the Twins have some pitchers throwing well at Class AAA Rochester. "We talked about different scenarios, but we haven't made any decisions."

Rough day for Arcia

As if Oswaldo Arcia's day wasn't bad enough Sunday, with a pair of costly misplays in the outfield, he went 0-for-2 at the plate as well. He also walked twice, which the Twins take as an encouraging sign, but the second-year Venezuelan outfielder still is mired in a slump.

Arcia batted .378 with four home runs in his first 11 games after returning from a wrist injury in mid-May. But since June 6, when he returned one day after turning an ankle against Milwaukee, little has gone right; Arcia is 2-for-25 over the past eight games, with nine strikeouts and no homers.

A slump is one thing, Gardenhire said, but the Twins want Arcia to avoid putting extra pressure on himself, which triggered a downward spiral almost exactly a year ago, one that got so bad, Arcia struck out 12 times in 15 at-bats and was sent to Rochester.

Gardenhire said the same symptoms are back, with Arcia "swinging at sliders in the dirt or over his head," so Twins hitting coach Tom Brunansky has been working with him. "He's just got to get better pitches in the zone. It looks like he's trying to hit an eight-run homer every time up," Gardenhire said. "He's got to calm his swing down. He's trying to hit the ball 8,000 miles right now. He's swinging like a madman."

Plouffe lands on DL

Third baseman Trevor Plouffe woke up with the flu Sunday, but that wasn't his worst ailment. His left side still was sore, too, from a diving attempt at a ground ball during Saturday's game, so the Twins placed their RBI leader on the 15-day disabled list because of what a magnetic resonance imaging exam revealed to be "inflammation between the ninth rib and costal cartilage." Soreness, in other words, but not the strained oblique they had feared, an injury that might have kept him out several weeks.

"We're hoping it won't take quite as long to heal up," Antony said. "He thought he had the wind knocked out of him initially, and wanted to stay in the game. When he got the ball and threw it, he realized he was a lot more sore than he thought."

Pedro Florimon was summoned from Rochester, where he had been hitting .230 since being sent down on May 8. Florimon's presence was essential, Gardenhire said, because Eduardo Nunez also was unavailable Sunday after he suffered a strained right hamstring Saturday. Nunez ran briefly on Sunday, and should be ready in another day or two.