HOUSTON -- The retirement of Jason Castro and the departure of Christian Vázquez in free agency this offseason has opened the door for catching prospects Korey Lee and Yainer Diaz to battle it out for the backup job behind steady veteran Martín Maldonado this year.

The Astros toyed with the idea of bringing in a veteran backup behind Maldonado, but they appear to be set letting their youngsters handle the load when Spring Training begins next month. It’s an opportunity not lost on Lee, the former first-round pick who made his debut last year.

“I’ve just got to play my game,” Lee said. “That’s what I pride myself on. I’m not going to try to be anybody else. I’m going to do what Korey can do and not put any pressure on myself. At the end of the day, whatever I can do to help the team win, that’s what I’m going to do. I will be a good opportunity.”

Ranked as the Astros’ No. 7 prospect by MLB Pipeline at the end of last season, Lee spent most of 2022 in Triple-A. He slashed .238/.307/.483 with 25 homers and 76 RBIs in 104 games with Sugar Land, striking out 127 times in 446 plate appearances. He had some ups and downs mechanically at the plate but has an elite arm behind it, which is key considering the emphasis on defense and run prevention the Astros place on their catchers.

“Obviously, my focus is at catcher,” Lee said. “I think you’ve got to put that first over the hitting. Obviously, I’m going to hit every day [in the cage]. Just on the defensive side, a lot of receiving [work], a lot of talking to the pitchers out on the field and just learning what they want to do. Strong relationships [are] the main priority to me right now.”

Lee, who lives in Houston, has been working out at Minute Maid Park each morning, hitting and catching bullpens. Among the pitchers he’s caught so far are Ryan Pressly and José Urquidy, each of whom will be playing in the World Baseball Classic next month, as well as lefty Blake Taylor.

Lee, 24, was called up to the big leagues on July 1 of last year when Castro was placed on the injured list. He stayed with the Astros for a month and was sent back down to Triple-A when they acquired Vazquez in an Aug. 1 trade with Boston. When rosters expanded a month later, it was Diaz, not Lee, who got the call.

When it comes to his competition with Diaz, it’s an amicable one. But it’s still a competition. Diaz, the team’s No. 3 prospect, could get the first shot to make the club this year because of his bat (he could DH and play some first base). Behind them, Cesar Salazar and Luke Berryhill are the next wave of catchers who will be in camp.

In 26 plate appearances with the Astros last year, Lee was 4-for-25 with nine strikeouts. Three of those hits came on July 10 in Oakland, where several former college teammates from Cal were in the stands. He went 3-for-4 with a double and three RBIs while catching seven scoreless innings from starting pitcher Jake Odorizzi.

“It was unbelievable,” Lee said. “It was a great learning experience for me, especially [my] first time up there, being with someone like Maldonado and Castro. Especially the team we had. There’s a lot of good guys to look up to, and I’m excited for this year to replay it again.”

Both Lee and Diaz were on the taxi squad for the postseason, meaning they were in the dugout with the team and traveled on the road. Just prior to Game 6 of the World Series, Lee was informed by manager Dusty Baker he would be activated for the game because of Yuli Gurriel’s right knee injury. Lee didn’t play in the Astros’ 4-1 victory over the Phillies to win the World Series, but the experience was invaluable.

“Seeing the atmosphere and going to the different stadiums and the crowd, it was a dream come true,” he said. “I got to experience it, and hopefully this year I get to play in front [of the crowds again]. You’re better whenever you get those opportunities to shine.”