MILWAUKEE -- Batting just .229 through his first nine games for Triple-A Memphis this season, outfielder Drew Robinson wasn't expecting the call on Sunday night informing him that he was heading back to the Cardinals ahead of their three-game series at Milwaukee.

"When I saw [Memphis manager] Ben Johnson on the phone, I was kind of shocked," Robinson said. "That is how it works on [the] 40-man [roster]. Even if you aren’t playing as well, I have seen it before -- even in the Minor Leagues. There are only nine games, so you can’t go too much off that.”

Robinson played all over the field for the Redbirds. He saw action at second base, shortstop, center field and left field this season and will likely fill a similar role with St. Louis.

“Versatility," manager Mike Shildt said when asked what Robinson can provide. "He gives us a lefty off the bench, but also the ability to play outfield, including center and anywhere in the infield pretty much.”

Acquired last December from the Rangers, Robinson entered Monday's game hitting .201 with nine home runs and 22 RBIs in 249 career plate appearances in the Majors, including going 0-for-3 for the Cardinals earlier this season.

He replaces right-hander Giovanny Gallegos on the active roster. Gallegos allowed a solo home run to Cincinnati's Yasiel Puig in Sunday's 9-5 victory in Monterrey, Mexico. He appeared in two games overall and struck out four batters over 1 2/3 innings.

St. Louis also returned utility man Yairo Muñoz to Memphis Monday. Muñoz had been on the Cardinals' roster as a 26th man during the Monterrey series.

Bader sits again

Harrison Bader, still bothered by a sore left hamstring, was not in the starting lineup for Monday's series opener at Milwaukee.

"Its still tight," Shildt said. "But he is doing a lot better and is checking all the boxes."

Shildt said it was unlikely that Bader would be available Monday against the Brewers, but would be re-evaluated before Tuesday's game.

"We don’t want to be over-aggressive with anything with the lower half [of the body]," Shildt said.

Martinez getting closer

Carlos Martínez threw 20 pitches during a bullpen session Monday in St. Louis, just his second since he was shutdown with shoulder weakness a week into Spring Training.

"Everything checked out great," Shildt said. "He tried to mix in four-seam [fastballs] and two-seam. He tried to mix in some spin and off-speed pitches and felt great.”

Martinez will get a few days off before returning to action. Shildt said the right-hander will go through his usual progression of side sessions, then throw live batting practice, probably at the team's Spring Training facility in Jupiter, Fla.

"He will face hitters, it looks like, on one of our days off," Shildt said. "Right now, we are working on his next side session.”