The Arizona Diamondbacks activated slugger Christian Walker from the 10-day injured list but also will be without outfielder Lourdes Gurriel Jr. due to a calf injury when they face the host San Francisco Giants on Tuesday night.

Gurriel was placed on the injured list, retroactive to Monday. The club is waiting on imaging to determine the severity of the injury.

Walker has been sidelined since sustaining a left oblique strain against the Washington Nationals on July 29. He had 23 homers and 71 RBIs in 107 games while batting .254.

Walker will start at first base and bat fourth in the opener of the three-game set against the Giants.

Gurriel injured his left calf while running to first base during the sixth inning of Sunday’s 11-6 win over the Los Angeles Dodgers.

Gurriel is batting .274 with 17 homers and 70 RBIs in 125 games.

The Diamondbacks (77-61) enter Tuesday in second place in the National League wild-card derby, one game behind the San Diego Padres and 2 1/2 games ahead of the Atlanta Braves.