Williamson injury update

Three days after colliding with a wall pursuing a foul ball, Mac Williamson was placed in concussion protocol, but he passed a variety of tests and avoided the concussion disabled list.

“I expect Mac to be in the lineup tomorrow,” manager

Bruce Bochy said after Friday’s win over the Dodgers.

Williamson didn’t feel immediate symptoms Tuesday after tripping over a bullpen mound and slamming headfirst into a wall. In fact, he hit a 423-foot homer in his next at-bat, his third homer in five games. But he was scratched shortly before Wednesday’s first pitch with a stiff neck.

On Friday, Bochy said, “He didn’t have any symptoms but did get a little lightheaded when doing some baseball activity a couple of days ago. That’s why he was shut down. He has not shown any symptoms since.”

To ensure they’d have a deep

bench Friday, the Giants called up outfielder Austin Slater from Triple-A Sacramento. Slater struck out as a pinchhitter and was optioned to Sacramento after the game.

In other transactions, reliever Josh Osich was placed on the disabled list with a hip strain, Chris Stratton (whose wife gave birth to a baby girl Wednesday) was reinstated and will start Saturday’s opener and reliever Derek Law was desigated as the Giants’ 26th man for Saturday’s doubleheader.

“Little faster start than I’m usually used to,” said Slater, who homered, doubled and singled Thursday to boost his Triple-A average to .358. “I usually start out slowly and get my feet wet and start rolling. But coming out of the gate, I’m hot this year so far and trying to keep the momentum I started last year when I was up here.”

Williamson’s on-field tests included batting practice — he put on another impressive show Friday — running and catching fly balls, and he was checked by doctors.

Briefly: Hunter Pence (right thumb sprain) played right field in his first rehab game at Sacramento because the Giants don’t want to move Chris

Shaw out of left field . ... Andrew

Suarez remains likely to start Tuesday against the Padres. Thursday in Sacramento, the lefty faced three batters over the minimum in seven innings of one-run, three-hit ball . ... Bochy confirmed reliever Will Smith (Tommy John surgery) will join the bullpen Tuesday or Wednesday. Smith looked good in back-to-back appearances in Sacramento and will make one more rehab outing Sunday . ... Reliever

Mark Melancon began his throwing program Thursday, playing catch from 60 feet.