HOUSTON -- Justin Maxwell was in the starting lineup for the 12th time in the last 14 games on Tuesday against the Royals, this time getting the nod in left field. He's started 15 games in center field, seven in left field and four in right field.

The consistent playing time is paying dividends at the plate for Maxwell, who's hitting .290 with three homers and nine RBIs since June 8 (prior to Tuesday).

"It's probably the first time I ever had the experience in the Major Leagues, playing five out of six days or six out of seven days," Maxwell said. "I'm just grateful for any opportunity. I'm thankful for the Astros. It's hard to get in a groove when you're only pinch-hitting or starting once a week. I'll just try to take advantage of it and have good at-bats."

Maxwell, claimed off waivers from the Yankees early in the season, has been starting more recently in center field against left-handers while making occasional starts at the corner outfield spots. He's hitting .276 against lefties and .210 against right-handers.

"There's no doubt the playing time he's getting, he seems to be getting more comfortable," manager Brad Mills said. "I think he's able to get in more of a routine of how he's doing things. We're hoping it continues, because he's really doing a good job for us now."

Norris set for rehab start at Oklahoma City

HOUSTON -- Right-hander Bud Norris, who was placed on the 15-day disabled list Sunday with a sprained left knee, is scheduled to start for Triple-A Oklahoma City on Saturday in a Minor League rehab appearance. The Astros right-hander will throw 75-80 pitches.

Norris will throw in the bullpen one more time on Wednesday before being sent out on rehab. Norris, 27, injured his hip flexor on May 31 against the Rockies, and wasn't the same as he dealt with leg and knee problems. He was 5-1 with a 3.34 ERA in his first 10 starts of the season, but just 0-3 with a 13.09 ERA in his next three starts.

Manager Brad Mills on Tuesday provided updates on some of the Astros' other ailing bodies.

• Outfielder Fernando Martinez (concussion) took batting practice on Tuesday and was given more post-concussions tests. Mills said Martinez is scheduled for even more tests with a doctor on Wednesday, with hopes he'll begin a Minor League rehab assignment on Thursday.

• Outfielder Travis Buck (right Achilles' tendinitis) went 0-for-2 in his first rehab game on Monday for Double-A Corpus Christi at San Antonio. Mills said Buck ran well and is progressing. Buck will play two or three games with Corpus Christi and three or four with Oklahoma City.

• Infielder Marwin Gonzalez (bruised right heel) took batting practice on Tuesday, but isn't quite ready for a game setting. "He's still sensitive to the touch, which enables him to go out there and do some work defensively, but at the same time he's not able to do everything," Mills said. Once Gonzalez is pain free, he'll be sent out.

• Right-hander Kyle Weiland, who made three starts for the Astros in April before an infection sidelined him indefinitely, had his peripherally inserted central catheter line removed recently and lost weight during his recovery. Mills said Weiland needs to build up his strength and muscle density before he can do anything. "It's going to be a long process," Mills said.

Luhnow working to sign Astros' Draft picks

HOUSTON -- With the University of Florida eliminated from the College World Series on Monday, Astros general manager Jeff Luhnow plans to begin contract negotiations with shortstop Nolan Fontana, a second-round pick, and outfielder Preston Tucker, a seventh-round pick in the 2012 First-Year Player Draft.

"I've made one phone call already this afternoon and plan to make another on [Wednesday]," Luhnow said. "Oftentimes, players coming off a long season want some time to rest, but that doesn't mean we can't be negotiating and trying to get a deal done. We're going to work hard to get these guys done as soon as we can."

The Astros have four picks among the top 10 rounds still unsigned -- Fontana, Tucker, fourth-rounder Rio Ruiz (third baseman from Bishop Amat High School in La Puente, Calif.), and catcher Tyler Heineman of UCLA, which was still alive in the College World Series as of Tuesday.

Luhnow said the sequence of how you sign players -- for example, signing the higher Draft picks earlier than lower picks -- matters when it comes to financial obligations and staying within the allotted bonus pool.

"Nobody wants to get to a point where you have to sign somebody to risk losing a pick, or you're not able to sign somebody because you risk losing a pick," Luhnow said. "There's definitely a sequence that matters, and I've gone through every situation of who we should sign and when."

Luhnow hopes to have another deal done with a top pick at some point during this homestand.