ARLINGTON -- Astros hitting coach Mike Barnett doesn't have to be reminded about how much his team has struck out in June.

The Astros were averaging 11.2 strikeouts per game in June entering Saturday's game against the Rangers and this season were second in the National League with 522 strikeouts (Milwaukee had 524). Barnett says the club has faced tough pitching, but his young lineup must improve.

"We talk about it almost every day," he said. "The thing is we've faced some strikeout pitchers and it's been tough. Without going into calls made against you and stuff like that, it's a fine [line] and we're going to try to get guys to get good pitches to hit. A lot of the strikeouts have been looking strikes, and I think guys are trying to do a conscientious job of getting good pitches to hit and not chasing, and sometimes it hasn't gone our way."

In three of the previous four games before Saturday, the Astros had faced Madison Bumgarner (12 strikeouts), Matt Cain (14 strikeouts in a perfect game) and Yu Darvish (11 strikeouts on Friday). Bumgarner, Cain, Darvish and the Mets' R.A. Dickey were tied for the league lead for the most double-digit strikeout games.

"We've faced a lot of those guys lately," Barnett said. "We can't make excuses for that either. We've just got to get better at it."

Astros call on Keuchel to debut on Sunday

ARLINGTON -- Dallas Keuchel was sleeping soundly in his hotel room in Round Rock, Texas, where the Astros' Triple-A affiliate, Oklahoma City, was playing, when RedHawks manager Tony DeFrancesco knocked on his door at 7:30 a.m. Saturday.

DeFrancesco told Keuchel to pack his bags and hit the road for Arlington.

The Astros announced Saturday that Keuchel, a left-hander drafted in the seventh round in 2009 out of Arkansas, will make his Major League by starting Sunday's series finale against the Rangers. Keuchel will start in place of Bud Norris, who's out with a sprained right knee and could be headed for the disabled list.

"That was a nice wake-up call," Keuchel said.

Keuchel, a 24-year-old who throws in the low 90s, went 5-4 with a 4.26 ERA in 13 starts for Oklahoma City. His stats were skewed by two terrible back-to-back outings May 19 at Reno and May 24 at Colorado Springs when he gave up 19 earned runs in 7 2/3 innings.

"Aside from the two starts on the West Coast, I think it's been pretty good," he said. "I'm commanding the ball right now and doing all the things I want to do, so I'm pretty pleased."

The Astros haven't officially activated Keuchel. They will have to make a corresponding roster move prior to Sunday's game, which could be putting Norris on the DL. Norris has lost his last three starts, but injured his hip flexor May 31 at Colorado before spraining his knee Tuesday in San Francisco.

"After talking with him and the trainers, it seems like it goes back to that hip flexor and the knee was kind of a problem because of the hip flexor," Astros manager Brad Mills said. "As he goes through this thing, he was still tentative. You can't be that way. It's hard to do anything being tentative. The last thing we need is for him to change his mechanics because of the way he felt. We're going to make sure it's all taken care of."

Lee activated as Astros send down Wallace

ARLINGTON -- Even though Carlos Lee hasn't put up anywhere close to the same kind of power numbers that he did earlier in his career in Houston, his return to the lineup on Sunday should provide a boost to the offense.

Lee was hitting .297 with four homers and 23 RBIs before straining his hamstring two weeks ago and going on the disabled list for only the second time in his career. The Astros activated him after Saturday night's 8-3 loss at Texas after he went 5-for-10 in three games on a rehab assignment at Double-A Corpus Christi. Brett Wallace was optioned to Triple-A Oklahoma City.

"He's not hitting for as much power, but he's at least a threat because of what he's capable of doing, and he can still reach the seats," Astros manager Brad Mills said of Lee. "He doesn't swing and miss very much and doesn't strike out a whole lot."

Wallace was called up when Lee was injured and had performed well while filling in for Lee at first base. He appeared in 11 games and hit .333 (12-for-36) with two homers and four RBIs. He went 0-for-3 with two strikeouts on Saturday.

"It's obviously not unexpected with Carlos coming off, so you're kind of prepared for it, but you definitely want to be here and be part of the guys and I did feel comfortable and had swung the bat well," he said. "It's just part of the game and I have to keep handling my business and hopefully get back here."