What can the Twins expect from Joe Mauer tonight?

It would be tough for him to duplicate May 1, 2009, when he returned from a rehab stint with Class A Fort Myers and hit a home run on his first swing.

That started an otherworldly month in which Mauer batted .414 with 11 homers, 32 RBI and an 1.338 OPS in 28 games. He went on to win MVP honors, as well as his third batting title.

This time, Mauer has more to prove after missing more than two months. Once again, he's returning without playing in a rehab game above Class A, though he did face Joe Nathan in a batting practice session Wednesday.

"Obviously, timing-wise and hitting-wise, I'm not right where I want to be, in mid-season form," Mauer said Thursday. "But more importantly it's, 'Can I catch back-to-back [days] or be out on the field and stay on the field for the rest of the year?'"

I agree. There is less concern about Mauer's offense than his defense and durability. He had a setback with his right shoulder during his rehab and worked hard to fix a glitch in his throwing mechanics, which he'd developed while trying to compensate for other injuries.

In 2007, Mauer threw out 53 percent of his opposing basestealers. That number dipped to 26 percent each of the past two years and 20 percent (2-for-10) in the nine games he caught this year before going on the DL.

The Padres will give Mauer a good test. They rank second in the National League with 64 stolen bases (through 70 games). Jason Bartlett leads the team with 12 SBs, followed by Will Venable (11) and the injured Orlando Hudson (10).

Tonight's starting pitcher, lefthander Brian Duensing, does a good job holding baserunners, as does Saturday's starter, Scott Baker. But the Padres will try to take advantage of any opening they get, especially as the lowest-scoring team in the majors, at 3.3 runs per game.

Note: Check back here later for the starting lineups.