SEATTLE -- Jose Altuve, George Springer and Aledmys Diaz will each require a Minor League rehab assignment before returning to the Astros, but the club has been encouraged with the progress each has made during their rehab on its six-game road trip.

Altuve (right leg) took batting practice on the field back-to-back days for the first time since rejoining the club after being pulled back from a rehab assignment. He did so showing strength pushing off his back leg on his swing follow-through, Hinch said, which has been Altuve’s most concerning issue, given that the former MVP underwent surgery on his right knee last October.

Altuve, who has been out since May 10, also took infield ground balls for the second day in a row, and he will run again on Wednesday after running on Monday.

“Jose, that's the most confidence that I've seen him run with and slow down with,” Hinch said. “More importantly, it's the slow down for him.”

Springer has taken the biggest leap forward of all Astros on the mend, Hinch said, which is encouraging, given that his initial prognosis when he was pulled from a game on May 24 appeared far more severe. Springer sprinted on Monday while hollering that he was at 90 percent. The All-Star center fielder is expected to take BP on the field on Wednesday.

“That's good. A loud George is a happy George,” Hinch said.

Diaz took infield grounders for the first time on Tuesday and BP, one day after running in the outfield with Altuve and Springer.

Diaz, Springer and Altuve have all missed the past seven games, though the Astros are 6-1 in that stretch. Hinch said that each will require a Minor League rehab assignment, but when they’re deployed won’t be determined until the club returns to Houston this weekend at the earliest.

• The club is hopeful that right-hander Collin McHugh (right elbow discomfort) will throw off a mound before it leaves Seattle on Thursday, but it’s possible he won’t do so until it returns to Houston. McHugh, out since May 21, has been playing catch.

• Catcher Max Stassi (left knee soreness) will report to the club’s Spring Training facility in West Palm Beach, Fla., to ramp up his rehab, beginning with catching Joe Smith’s live BP session this weekend. He’ll also catch a few bullpen sessions.

• Shortstop Carlos Correa remains in Houston as he continues to recover from the cracked rib that he suffered last Tuesday at his home while receiving a massage.

Martin optioned, Guduan recalled, Valdez added to rotation

One day after exhibiting prolonged command issues in Monday’s start against the Mariners, right-hander Corbin Martin was optioned to Triple-A Round Rock. Left-hander Reymin Guduan was recalled, and lefty Framber Valdez, who pitched a season-high four innings in relief (all shutout) on Monday, will slot into the rotation and start Saturday at home against the Orioles.

Valdez was vying for the No. 5 rotation spot in Spring Training, but he ultimately broke camp in the bullpen. Hinch said that Valdez is stretched out to throw a high-70s, low-80s pitch count. He threw 65 on Monday, 21 more than his previous high in ‘19. The rookie has a 3.12 ERA in 26 mostly low-leverage innings. Guduan, who lost the battle to Valdez for the final roster spot in camp, has pitched in just three games this season and given up two runs on three hits and two walks over 2 2/3 innings.

Martin, the club’s No. 4 prospect, per MLB Pipeline, pitched a combined 10 innings over his past three starts, with a 7.20 ERA. Over his five total starts, he’s given up eight home runs in 19 1/3 innings, while striking out 19 and walking 12. Martin has also thrown 38.7 percent of his pitches this season while behind in the count, which is the most in the Majors among 173 qualified starters.

“I think it was important for us to be realistic with him and not waste any more time of the same thing over and over again,” Hinch said. “We had to mix something up and make a change, just given the fact that he'd gone three innings and three innings and three innings. He can make a quick adjustment. His stuff is really good.”