WEST PALM BEACH, Fla. -- The Astros’ first injury of Spring Training -- a strained right quadriceps muscle suffered by hard-throwing right-hander Josh James – leaves veteran right-hander Brad Peacock and young lefty Framber Valdez as the top remaining candidates for the fifth spot in the team's starting rotation.

James, who made his big league debut last September and was throwing 100 mph in the postseason, strained his right quad while lifting weights following his live bullpen session on Sunday on the back fields at Ballpark of the Palm Beaches. He’s the No. 62 overall prospect, per MLB Pipeline.

“What was already a slow spring for him will now turn a little bit slower,” Astros manager AJ Hinch said Wednesday. “He’ll now not pitch for a little bit.”

Several Astros pitchers are on individualized throwing programs this spring, including James, who threw a combined 137 1/3 innings last year between the Astros and the Minor Leagues. Hinch said James “looked great, felt great” while throwing on Monday. He was lifting weights as part of his post-throwing workout and strained his quad. Although he’s not going to get on the mound for a while, he did play catch Wednesday.

“It’s very frustrating, but I know everything happens for a reason,” James said. “Just sticking to my plan and process and just keeping my head down and going back to work and focusing on the things I need to focus on and get healthy and get strong and be ready.”

James, 25, was named the Astros’ Minor League Pitcher of the Year after going a combined 6-4 with a 3.23 ERA with 171 strikeouts in 23 games (21 starts) at Triple-A Fresno and Double-A Corpus Christi. He was called up Sept. 1 and dazzled with his 101-mph fastball, striking out 29 batters in 23 innings in six games (three starts) with the Astros.

“We still think he’s going to get enough outings to factor in the bullpen conversations,” Hinch said. “Disappointed, obviously, that his quad’s bothering him.”

Peacock, 30, made a career-high 61 appearances last year, with all but one coming in relief. He was a reliable starter in 2017, going 10-2 with a 3.22 ERA as a starter. He’s the longest-tenured pitcher on the team.

Valdez, 24, made his big league debut in August and posted a 2.19 ERA in eight games, including five starts. Though he struggled with his control at times, Valdez generated ground balls at a high rate and was especially tough on left-handed hitters.

“It limits our options,” Hinch said. “I’ve said this before. We’re really trying to put the puzzle together of the roster. Provided [James is] healthy enough to factor into the bullpen, we still have a couple of options for the rotation. Obviously, we’re looking for somebody to step up.”

Hinch said top pitching prospects Forrest Whitley, Corbin Martin and J.B. Bukauskas aren’t going to break camp with the team. He said right-handers Rogelio Armenteros and Brady Rodgers may pitch more with James down. Lefty Cionel Perez might get stretched out some, too, when he gets on the mound. He’s about a week away from getting into games.