Paul Molitor has been watching replays of Ervin Santana's starts lately. Pinpointing the problem is easy, he said. Solving it, that's the tricky part.

"Missing his spots with the fastball is a big part of where it starts," the Twins' manager said. Pitching coach Neil Allen has spotted some minor mechanical adjustments, Molitor said, and has been trying to help the veteran righthander incorporate them as he prepares for today's game against the Astros.

"He's been working hard between his starts," Molitor said. "He's had enough experience to where you hope something clicks for him."

Santana has a 9.12 ERA in his five August starts, and doesn't have a win since July 23. And he's been even worse in Target Field: a 9.77 ERA in his three home starts, with opponents batting .343 against him.

The 32-year-old Santana has a carefree air about him, smiling through all the losses. But Molitor said fans shouldn't take that as a sign he doesn't care about how he's pitching. "I know he's got a little bit different demeanor, he's not a real external guy in terms of what you see out there," Molitor said. "But I know that's not indicative of the passion and the competitiveness that he has. I know he wants to help us out here, and hopefully today is the beginning of that."

The Twins can win their third straight series with a victory, important with another 10-day road trip looming next weekend.

Trevor Plouffe is getting a breather today, after playing every game this month. Eduardo Nunez, who homered on Friday, will start in his place.

"People aren't always happy when I make those decisions. He's been at it consistently for us. He's had a good year," Molitor said. "But it seems like he's been battling a little bit. [This will] give him a chance to back off, and then get back in there" on Tuesday.

Kurt Suzuki and Torii Hunter also get the standard day-game-after-a-night-game break, with Chris Herrmann and Shane Robinson taking their place. On the Houston side, shortstop Carlos Correa remains out with a hamstring injury, meaning Twins fans won't have a chance to see the likely AL Rookie of the Year until next season.

Here are the lineups for today's series finale with Houston:

ASTROS

Altuve 2B

Gonzalez SS

Gattis DH

Rasmus RF

Gomez CF

Valbuena 3B

Carter 1B

Conger C

Marisnick LF

McCullers RHP

TWINS

Dozier 2B

Escobar SS

Mauer 1B

Sano DH

Rosario RF

Nunez 3B

Robinson LF

Herrmann C

Buxton CF

Santana RHP