One of the best batteries in baseball is back in action.

The Giants activated right-hander Kevin Gausman from the Family Medical Emergency list and reinstated catcher Buster Posey from the 10-day injured list ahead of Monday’s series opener against the Los Angeles Dodgers.

Gausman was expected to open the second half on the mound for the Giants in St. Louis, but missed the three-game series after his wife Taylor was hospitalized with pregnancy complications. He’ll now take the ball for the first time since the All-Star break and face Dodgers right-hander Tony Gonsolin on Monday.

The right-hander was named an All-Star for the first time with one of the best first half performances of any Giants pitcher in franchise history. In 18 starts, Gausman posted a 1.73 ERA with a 0.820 WHIP while striking out 133 batters in 114 2/3 innings.

The Giants had hoped Posey would be available to return from the injured list to play against the Cardinals, but a left thumb contusion and bone bruise he suffered on July 4 required a few extra days to heal. Posey participated in light baseball activities over the weekend at Busch Stadium and is back in the starting lineup for the first time in two weeks.

Posey was named to his seventh career All-Star team after batting .328 with a .968 OPS in 201 at-bats before being placed on the injured list.

To clear space for Gausman and Posey, the Giants optioned left-handed reliever Caleb Baragar and backup catcher Chadwick Tromp to Triple-A Sacramento.

Baragar did not pitch for the Giants after being recalled July 11 while Tromp started Sunday’s game behind the plate after veteran Curt Casali caught the first two games of a three-game set in St. Louis.