HOUSTON -- A pair of rookies awaiting their Major League debut swooped in to earn spots on the Astros’ Opening Day roster, with top prospect Cam Smith getting the nod as the starting right fielder and No. 21 prospect Ryan Gusto earning the final bullpen spot.

Meanwhile, two of the Astros’ best position players from the past few years -- Alex Bregman and Kyle Tucker -- are with other clubs, but the roster turnover from last year doesn’t stop there. Of the 26 players to make Houston’s Opening Day roster this year, only half (13) were on the team’s roster last year to begin the season.

Houston still returns a solid core, anchored by Jose Altuve, who moves to left field, Yordan Alvarez, Yainer Diaz and newcomers Isaac Paredes and Christian Walker. The rotation includes four players who made at least 28 starts last year, but most of the turnover is in the bullpen.

Only Josh Hader and Rafael Montero were on the team’s Opening Day roster last year (Bryan Abreu was suspended for the first two games of 2024, so he wasn’t technically on the Opening Day roster).

Here’s a look at this year’s 26-man Opening Day roster:

Catchers (2): Yainer Diaz, Victor Caratini
Diaz will be the starting catcher, with Caratini backing him up for the second year in a row. The pair combined to start all but seven of the Astros’ 161 games last year.

First baseman (1): Christian Walker
Walker, who signed a three-year deal worth $60 million on Dec. 23, was limited to eight Grapefruit League at-bats because of an oblique injury, but he will be in the lineup on Opening Day. He’s won three consecutive Gold Gloves in the NL and represents a big upgrade at first base from 2024.

Second baseman (1): Mauricio Dubón
Altuve has started at second base on Opening Day in 12 of the past 13 seasons (he was injured in 2023), so his move to left field marks the end of an era. Dubón will split time with Brendan Rodgers at the position and will continue to fill a utility role.

Shortstop (1): Jeremy Peña
Peña had a terrific spring at the plate and could be poised for his best season yet in his fourth year in the big leagues.

Third baseman (1): Isaac Paredes
Acquired from the Cubs in the Tucker trade, Paredes will become the first person not named Bregman to start at third base on Opening Day for the Astros since 2016. Paredes' pull power should fit well with the Crawford Boxes.

Outfielders (4): Jose Altuve, Jake Meyers, Cam Smith, Chas McCormick
With the Astros preferring for Alvarez to get most of his at-bats at DH and Tucker having been traded, Altuve moves to left field. Meyers will start in center and Smith begins the season in right field -- a position he hadn’t played until midway through the spring. McCormick can play all three outfield spots.

DH (1): Yordan Alvarez
The slugger started 53 games in left field last year (and 94 at DH), but the team wants to keep him at DH for the most part this year to keep him healthy.

Bench/Utility (2): Brendan Rodgers, Zach Dezenzo
Rodgers, who won a spot as a non-roster invite in the spring, is a former Gold Glove winner at second base. Dezenzo, who had a great spring and earned his first Opening Day roster spot, can play the corner outfield and infield spots.

Starting pitchers (5): Framber Valdez, Hunter Brown, Spencer Arrighetti, Ronel Blanco, Hayden Wesneski
Valdez, Brown, Blanco and Arrighetti -- each of whom made at least 28 starts last year -- will anchor the rotation. Wesneski, acquired from the Cubs in the Tucker trade, is the No. 5 starter.

Relief pitchers (8): Josh Hader, Bryan Abreu, Tayler Scott, Bryan King, Rafael Montero, Luis Contreras, Steven Okert, Ryan Gusto
Hader (closer) and Abreu (setup) are the anchors, but the club also returns Scott, who had a 2.23 ERA last year in 62 games before ending the season on the IL. There’s a lack of experienced depth after that, with lefties King and Okert and right-hander Contreras being counted on to get key outs. Montero, who was DFA’d last year, earned a bullpen spot as he hopes to recapture his 2022 form. Gusto has been a starter in the Minor Leagues.