Cubs lefty Drew Smyly scratched; Scott Effross starts vs. White Sox

Hours before the first pitch Tuesday against the White Sox, the Cubs announced a change in starting pitchers.

They put left-hander Drew Smyly on the bereavement list and started side-arming right-hander Scott Effross.

Effross, who made his major-league debut last season, entered the game with a 1.80 ERA in 10 innings.

‘‘His profile helps — just the ability to get the ground ball, the ability to strike guys out and the ability to throw strikes,’’ manager David Ross said of the confidence he has putting Effross into a number of situations. ‘‘He seemed to handle each moment I’ve thrown at him really well. And he did that last year and continues to grow into that.’’

It was the first start of Effross’ big-league career, as he served as the opener for the bullpen game.

‘‘I think that’s a good choice,’’ catcher Willson Contreras said of Effross starting. ‘‘He’s been throwing the ball well and will adapt to a starting role. I know it’s only one game, but the mindset has to be different, and I think he’s going to have the ability to adapt to it.’’

Effross allowed two runs, both unearned, in 1„ innings before multi-inning reliever Keegan Thompson replaced him.

The Cubs also made a pair of moves to fill out their active roster and reinforce their pitching staff. They called up right-hander Robert Gsellman, whom they signed to minor-league deal this spring, from Triple-A Iowa. To make room for him on the 40-man roster, they designated left-hander Locke St. John for assignment.

Contreras day-to-day

Contreras was out of the lineup for what Ross called ‘‘a little something’’ but ‘‘nothing serious.’’

Ross declined to get into specifics, citing competitive-advantage reasons, but when he was asked whether it was an upper- or lower-body injury, he said, ‘‘Mid.’’

Ross said Contreras was available off the bench, if necessary.

Contreras hasn’t caught in a game since the Cubs’ 11-1 loss Friday in Milwaukee. He served as the designated hitter Saturday.

Frazier back with team

Outfielder Clint Frazier was back in the clubhouse with his teammates for the first time since undergoing an appendectomy a week and a half ago. In the food room, Frazier told Ross he was ready to return.

‘‘I told him I was more [ready] than he was,’’ Ross said. ‘‘We had a big debate. I think he was right, probably.’’

Ross wasn’t ready to pick up a bat, but the Cubs don’t want to rush Frazier back, either. He said he still can feel the incision site in his belly button when he bends backward.

‘‘I definitely think I could swing right now,’’ Frazier said. ‘‘But I don’t think the path moving forward will be that quick. But I feel a lot better.’’

Frazier has been cleared, however, to ride the stationary bike and do light exercises.

‘‘Following the timelines of other guys, it seems like the window is three to five weeks,’’ Frazier said. ‘‘So I think I’m definitely on time for that, depending on what they let me do.’’