CHICAGO – The Twins had their energetic leadoff man back in the lineup Tuesday.

Luis Arraez returned from the seven-day injured list in time to start in left field at Guaranteed Rate Field against the Chicago White Sox. Arraez had been out because of a concussion after a collision at home plate more than a week ago against Texas.

"Luis is full go," manager Rocco Baldelli said of Arraez's recovery from headaches and dizziness. "We'll see how he responds to game action and being out there on his feet all day long. I'm assuming he'll take to it well."

Arraez said as much Sunday, remarking how antsy he was to return to playing alongside his teammates. His inclusion in the outfield was a new look for the Twins, with Max Kepler in center field and Trevor Larnach in right.

Infielder Nick Gordon, who was 1-for-2 in his major league debut Thursday, was sent to St. Paul when Arraez was activated.

Injury update

Center fielder Byron Buxton is on the 10-day injured list, although he might be out longer because of a hip flexor injury.

"It's mainly rest and mainly treatment in the training room," Baldelli said of Buxton's activities. "So he's been posted up in the training room getting worked on pretty much most of the time. Once he gets to a certain point — I'm not sure when that point's going to be — but once you get to a certain point, then you begin the ramp-up into all of the baseball activities and throwing, hitting, running."

Alex Kirilloff is in a similar holding pattern because of a right wrist injury. The first baseman/outfielder saw a specialist and received a cortisone injection last weekend and planned to test his wrist to see if he could play through the pain or if he might eventually need surgery.

"He hasn't swung yet, so I think we're getting to that point," Baldelli said. "Obviously with the off day [Monday], I encouraged all of our guys to take advantage of that off day as best they could. It's not going to affect AK's schedule in any way. So now that we're back at the field, I think he's getting treated again, in the training room as he will be, and they're going to decide when he's going to swing the bat."

New ball revelations

Andrelton Simmons hadn't realized MLB had tweaked its baseballs ahead of this season, a subtle change intended to deaden the distance by one or two feet on balls hit 375 feet or more.

When the Twins shortstop learned of that Tuesday afternoon, a few things might have started to make sense.

"It's definitely different," Simmons said of hitting now vs. when he made his major league debut in 2012. "Guys are throwing harder, spins are tighter. I've been striking out a little more than I'm used to. Guys stuff-wise look a little sharper."

Simmons, known more for his defense than offense, entered Tuesday with 15 strikeouts in 22 games this season, nearly equal to his 17 hits. He had 16 strikeouts through 30 games in last year's shortened season.

"Most teams' bullpens are pretty good. Guys come in, and it's not a guy throwing 88 with a two-seamer. It's a guy with a nasty sinker or nasty slider or a good split or really good spin rate," Simmons said. "You've got to respect all these guys coming in nowadays, more, I feel like, than when I first came up."

Team spirit

Baldelli said having Arraez, Buxton and Kirilloff all still on the road trip during their rehabs was a boon to all involved.

"There's actual real benefit to the players but also to the team and to their teammates and the rest of the group, especially guys that are big parts of what we do and are established in here and have relationships with the guys next to them," Baldelli said.

"Guys do appreciate and respond well to being around everything going on, and it helps them focus, and it helps them when they return to be ready to go."