CINCINNATI -- After some hope from the Tigers, Doug Fister will not be able to return when he's eligible to be activated from the 15-day disabled list on Wednesday. Still, he shouldn't be far off.

Fister, sidelined for the past week and a half with a left side strain, threw his first mound session Saturday afternoon and felt sore on Sunday. For now, though, the Tigers are treating it as a typical reaction to picking up the intensity on his throwing.

Fister will rest for another day or two, then throw another session and see how he feels, head athletic trainer Kevin Rand said Sunday. If he feels fine after that, he should be close to a return.

With Wednesday out of the question for Fister, the start that night against the Cubs will fall to Rick Porcello on his regular four days' rest. Justin Verlander will still start Thursday afternoon's series finale against the Cubs.

Casey Crosby, whose spot will be skipped coming out of Monday's off-day, will be available out of the bullpen for the next couple days before rejoining the rotation for Friday's series opener against the Rockies at Comerica Park.

Boesch scratched with sore right ankle

CINCINNATI -- Brennan Boesch described his slide into home plate Saturday as a "crazy ninja jump."

He didn't mean it in a good way. His right ankle, which was caught underneath his leg on the slide, didn't care for it either.

"On video, you couldn't really see what was happening underneath my leg when I slid," he said. "This is the foot that's tucked under. I slid with my left leg. It's like I started sliding at third base. I wanted to get that run so bad I started sliding like 50 feet in front of home plate. I wasn't sure if I was going to have to take the catcher out. I was going to be safe one way or the other."

Boesch was optimistic that an afternoon of treatment and workouts would get the sprained ankle strong enough to let him play Sunday night's series finale against the Reds. Once he started running, though, he didn't have the range he felt he needed to give himself a fair chance at a running play.

Thus, Boesch was scratched from the Tigers' lineup. Quintin Berry, who had been starting in center field until Austin Jackson returned from the disabled list Saturday, replaced him in right field and batting second.

The good news for Boesch is that there's very little swelling, which leaves him "pretty fairly optimistic" that he can return to the lineup Tuesday night against the Cubs at Wrigley Field.

Officially, he's day to day. But with as many injuries as the Tigers have had, manager Jim Leyland expected that.

"Everything's day to day with us this year," he said with a hint of exasperation.

Boesch would play a key role in the Tigers' four-run eighth inning later in the evening. Pinch-hitting for Brayan Villarreal, Boesch singled off Aroldis Chapman to load the bases and was replaced by pinch-runner Hernan Perez.

Perez in awe of first Major League game

CINCINNATI -- Hernan Perez got the call to the Major Leagues around 9:15 a.m. on Saturday and thought it was a practical joke. Guys playing at Class A Lakeland don't get called up to the big leagues.

"I said, 'Really? I don't believe it,'" he said.

Sometime between the call and the 11:15 a.m. flight he had to catch in Orlando, Fla., about an hour away, he realized they were serious and got packing to replace Jhonny Peralta, who had gone on paternity leave.

He had to connect in Atlanta, then had to count on some deft driving from one of the visiting clubhouse personnel from Great American Ball Park to get him in from the airport. But he arrived shortly before game time.

By the seventh inning, the 21-year-old second-base prospect was making his big league debut as a pinch-hitter. He was still in awe after the game.

In fact, for his first Major League game as a player, he sounded more like a fan.

"For me, my first big league game, I saw [Justin] Verlander pitch, [Jose] Valverde closing, Prince [Fielder] homer. I'll never forget it," Perez said.

In the ninth inning of Sunday's 7-6 victory, Perez beat out an infield single to third for his first Major League hit. He was optioned back to Class A Lakeland after the game to make room for Peralta's return Tuesday.

Quick hits

Jhonny Peralta will return from paternity leave and rejoin the Tigers on Tuesday in Chicago. His wife, Molly, gave birth to twin girls, Gabriela Rose and Laina Katherine, on Saturday in Cleveland. The Tigers activated him after Sunday's game and optioned Hernan Perez back to Class A Lakeland. Perez scored in the eighth-inning rally Sunday night and recorded his Major League hit in the ninth inning.