ATLANTA -- The Astros were forced to make a change to their World Series roster on Saturday when backup catcher Jason Castro was placed on Major League Baseball’s joint COVID-19 protocols list and replaced by catcher Garrett Stubbs, who was on the taxi squad.

Astros general manager James Click didn't say if Castro tested positive for COVID-19 or if he could possibly return in the next few days. In accordance with MLB postseason rules, Stubbs may remain on the active roster until Castro is approved to be reinstated from the COVID-19 related injured list.

“This team has been through a lot of bumps and bruises and difficult situations like this,” Click said. “It’s obviously unfortunate timing. Jason is a huge part of this team. We were looking forward to him getting some big hits for us in the World Series. We’ve been through this kind of stuff before, and we’ll be fine.”

Castro, who re-signed with the Astros prior to the start of this season, appeared as a pinch-hitter in Houston’s Game 3 loss. He went 1-for-1 with a walk and hit his first career playoff homer in Game 2 of the American League Championship Series against the Red Sox.

Stubbs appeared in 18 games in the regular season for the Astros, going 6-for-34 (.176) at the plate. A left-handed bat, Stubbs could also be utilized as a pinch-runner or play left field, if needed.

Stubbs said he was sitting at his locker a few hours before the game when Click summoned him to manager Dusty Baker’s office and told him the news.

“Dusty joked, saying that I was batting cleanup tonight,” Stubbs said. “That’s how the conversation started off. I laughed at him and he said, ‘Why are you laughing?’ And then he told me I was going to be active tonight.”

Stubbs said he feels “awful” for Castro, but is ready to step up in his absence. He said he’s been in the dugout going over each batter with starting catcher Martín Maldonado after almost every game.

“The way my opportunity came, that’s just how it goes sometimes,” Stubbs said. “It’s tough for him. I’m sure he’s going through a lot of emotions right now. This is an opportunity for him and now for me. We’ll talk after the World Series goes. I know he’s rooting for me and we’ll try to get the W tonight.”