CHICAGO - Twins third baseman Trevor Plouffe is in a race against time to prove his fitness or land on the disabled list.

Plouffe is using stronger medication on his bruised right thumb, hoping it will help him get back on the field in a couple days. But if he can't play by Friday, the Twins could place him on the disabled list. The move could be backdated to July 20, when Plouffe jammed the thumb while batting against the Royals in Kansas City, so he could be eligible to come off the DL on Aug. 6.

"I can let it go through [Wednesday], then maybe we will see," Twins manager Ron Gardenhire said. "I don't think he can tell us when he's going to be able to play yet. We're just going by what the doctors say. If that's the case, maybe by Friday if there's vast improvement, then Friday can be a legit day.

"But if we come down to Thursday and he goes in and it's still [bothering him], then we might have to make a move."

Danny Valencia is a candidate to fill in at third if the Twins have to place Plouffe on the disabled list. Valencia is batting .249 with seven homers and 36 RBI at Class AAA Rochester. While Valencia hasn't had a great season, he looms as the best third baseman available, unless the Twins bring up another infielder.

"Once we get to a situation where we have to start considering it, then we will call down there and see what those guys have to say," General Manager Terry Ryan said. "He's made a lot of progress in the last day."

Morneau returnsArmed with celebratory stogies -- and a stiff neck -- Justin Morneau rejoined the Twins.

He left the team over the weekend to be present for the birth of his second child, a boy named Martin. The league grants players paternity leave for three days.

But he apparently slept wrong Monday night and had a sore neck Tuesday, so Gardenhire used Morneau as the designated hitter against the White Sox.

"He slept in a bad bed," Gardenhire said. "Or he slept wrong in a good bed. You can figure it out."

Morneau went 2-for-4 with a double.

The day after The Twins were left wondering how much Francisco Liriano's trade value was affected after the lefthander was knocked out in the third inning Monday. One bad start after 10 good ones shouldn't damage his tradeability that much, especially because pitching is coveted by playoff hopefuls.

Liriano's final start before the July 31 non-waiver trade deadline will be Sunday against Cleveland at Target Field. Ubaldo Jimenez is scheduled to start for the Indians.

The Yankees, Diamondbacks, Cubs, Padres, Tigers, Reds and Blue Jays were among teams with scouts at Tuesday's game, one day after many scouts filled the press box in the hours before Liriano's start. But Monday's game might have showcased both starting pitchers, because there were reports on Tuesday that the White Sox are trying to trade Gavin Floyd, who started for Chicago.

Etc. Darin Mastroianni started in right field because the White Sox started lefthander Jose Quintana, but went 0-for-4.

• Righthander Carl Pavano will throw another bullpen session Wednesday, as he works his way back from shoulder soreness. If that goes well, he'll likely head to Fort Myers, Fla., to continue bullpen sessions before the Twins decide on where he would begin an official minor league rehabilitation assignment.