SAN FRANCISCO -- Although Travis Buck is eligible to come off the disabled list on Wednesday, the veteran outfielder isn't close to returning. Buck has been disabled since May 28 with right Achilles' tendinitis.

Buck said the injury is improving, but he hasn't been able to test it out by running just yet.

"It's just a matter of trying to make sure it's pain free so it doesn't flare up again," he said. "I'll take a little precaution, but we just have to kind of base it off how it responds. I was able to run pretty hard the last day in Chicago [on Sunday]. I didn't sprint or anything, but did a pretty quick jog and did some multi-directional stuff in the outfield that held up pretty good."

Buck, who was hitting .216 in 74 at-bats but was flourishing as a pinch-hitter, will head out on a Minor League rehab assignment as soon as his body allows him to. But that's still down the road a bit.

"I'd like to get as many at-bats as I can to get my timing down," he said. "I would like to be able to produce and be comfortable up here, rather than rush just to get back."

Norris exits early after spraining left knee

SAN FRANCISCO -- Astros starting pitcher Bud Norris was removed from Tuesday's game against the Giants in the fourth inning with a left knee sprain.

Moments before being taken out of the game, Norris chased down a popup off in foul territory after catcher Jason Castro lost the ball off the bat. Norris sprinted after the pop in front of the third-base dugout and was unable to catch it while lunging forward.

Norris threw a few warmup pitches for manager Brad Mills and athletic trainer Rex Jones before leaving the game. He pitched 3 1/3 innings and allowed three hits and three runs, including a home run to pitcher Madison Bumgarner. He threw 80 pitches.

Norris, who grew up in the Bay Area cheering for the Giants, was pulled from his May 31 start against the Rockies with a strained hip flexor. He was able to make his next start, giving up seven hits and four runs in six innings Wednesday against the Cardinals.

Lee progressing, nearing rehab assignment

SAN FRANCISCO -- Carlos Lee, who's been on the disabled list since June 2 with a left hamstring strain, could be sent out on a Minor League rehab by the end of the week, manager Brad Mills said Tuesday.

Lee has been progressing so well that he's already hitting in the batting cage, and on Tuesday the first baseman fielded ground balls during batting practice and was throwing to bases. Lee worked out at a health club Monday with strength and conditioning coach Gene Coleman.

"I think the big part is running," Lee said. "I ran on Sunday and felt OK, but I didn't push it. I ran at about 60 percent and felt OK."

Mills said Lee would run again on Wednesday before being sent out for a couple of days on a rehab assignment. Lee is eligible to come off the DL for Sunday's game against the Rangers in Arlington.

"I definitely have to go," Lee said of a rehab assignment. "I have to be in a real game and push it a little bit and see how it responds."

Schafer still bothered by flu-like illness

SAN FRANCISCO -- With left-hander Madison Bumgarner facing the Astros on Tuesday, Houston manager Brad Mills stacked his lineup full of right-handed hitters. Mills said that's why center fielder Jordan Schafer wasn't in the lineup, but Schafer is still trying to shake an illness.

Schafer declined a request to be interviewed, saying only that he still doesn't feel well. Schafer has been dealing with a flu-like illness for more than a week. Sickness has made its way around the clubhouse in recent days, with Mills and third baseman Chris Johnson both overcoming illnesses.

"He's the only guy that seemed like was still under the weather, even though he stayed in bed most of the day [Monday]," Mills said. "We're hoping he can get out there and get moving around a little bit and take some swings and some fly balls. That might be the best thing for him."

Mills said Schafer has been examined by doctors and is on antibiotics.

"And believe it or not, he's starting to feel better, but it has drawn on for quite some time," Mills said.

Worth noting

• Outfielder Fernando Martinez, who's on the seven-day disabled list with post-concussion syndrome, was seen by a doctor on Monday in Houston and will see more specialists. Manager Brad Mills hopes Martinez is able to baseball activities by the end of the week.