DETROIT -- Jose Valverde continues to recover from a lower back strain he suffered in Chicago, and although he said he's feeling better, manager Jim Leyland ruled out the possibility of his return in Sunday's series finale against Pittsburgh.

"He's not pitching," Leyland said. "Day off tomorrow, hopefully [he'll be] ready to go Tuesday in Cleveland. Hopefully."

Valverde worked out on the field at Comerica Park on Saturday and played catch for the first time. He said after the game his back was still "a little tight," but that he wasn't nervous and would play catch again Sunday.

Austin Jackson hit in the cage off a tee Sunday morning and felt fine, he said Sunday afternoon, but when he tried running, he felt his abdominal strain tighten up. He'll rest it on Monday before getting treatment ahead of the team's flight to Cleveland.

Jackson said his injury continues to be a day-to-day situation, with no guarantee he'll be ready for Tuesday in Cleveland.

"It wasn't where I want it to be," Jackson said of his injury, "but I can feel it getting better. Hopefully it's [ready] in Cleveland."

Leyland: Villarreal compares to Alburquerque

DETROIT -- Tigers manager Jim Leyland went in a very interesting direction to describe Brayan Villarreal's potential in this year's Detroit bullpen.

He brought up Al Alburquerque.

"Right now, today, he'd probably fit right in [like] last year's Alburquerque," Leyland said after Villarreal's 2 1/3 perfect innings Saturday. "Maybe [pitching] a little bit earlier, but that type of thing. That would be great for us. I mean, that's a great arm, obviously."

When Alburquerque was on last year, his arm was tremendous, his slider devastating. And when the Tigers needed a big strikeout before getting to Joaquin Benoit and Jose Valverde for the eighth and ninth innings, Alburquerque was the guy.

Villarreal is a different type of a pitcher. He's a power arm, for sure, and his fastball cranked up to 98 mph on the Comerica Park radar gun Saturday. But Villarreal is throwing his slider less often, including just three times among his 23 pitches Saturday.

The big difference for Villarreal in his last two outings has been fastball command. He has pounded the strike zone with it, and hitters have struggled to catch up. Correspondingly, Villarreal has struck out seven of the 15 batters he has faced since the Tigers recalled him on Thursday, compared with just one of the seven hitters he faced in April.

When Villarreal lost a game at Yankee Stadium on two walks, a wild pitch and a passed ball, Leyland said he needed to relax and let his talent come out. The longer relief outings seem to have helped. Now they have to try to keep it that way.

"That would really be a big help to us," Leyland said. "That gives you another weapon in the bullpen in certain spots."

Despite inconsistencies, pitchers missing bats

DETROIT -- The Tigers haven't gotten quite the consistency they've wanted out of their pitching staff yet. One consistency they have found is in strike three.

With Max Scherzer's 15 strikeouts Sunday, the Tigers racked up double digits in strikeouts for the 12th time in their first 41 games. That's a first for them since at least 1918, as far back as game-by-game records go.

As streaks go, the Tigers' mark of 11 straight games with eight or more strikeouts is also their best strikeout stretch since at least 1918.

Scherzer's performance vaulted the Tigers past the Yankees for the American League lead team lead in strikeouts, having fanned 353 batters in 365 innings. Only the Washington Nationals have struck out more, with 362 over 374 1/3 innings.