DENVER -- The last-place San Francisco Giants have made a series of roster moves, including the promotion of outfielder Mac Williamson after he missed most of last season because of a concussion and its lingering effects.

Williamson and infielder Donovan Solano were selected from Triple-A Sacramento and lefty Williams Jerez was recalled from the minor league team before Tuesday night's game at Colorado.

Playing in left field and batting sixth, Williamson celebrated his return with a three-run home run in the fourth inning and an RBI single in the fifth.

The Giants' roster shake-up began after Monday's 12-4 loss at Cincinnati when the Giants optioned outfielder Mike Gerber and switch-pitcher Pat Venditte to Triple-A.

It continued when infielder Yangervis Solarte, who was hitting .205 in 28 games, was designated for assignment. Also, veteran outfielder Gerardo Parra became a free agent after deciding against going back to the minors -- he was batting .198 in 30 games after hitting .284 for Colorado last season.

Williamson's return to the Giants capped a long-running comeback story. He suffered a concussion when he tripped over a bullpen mound as he chased after a foul ball in April 2018 and persistent symptoms caused him to miss much of the rest of the season. He hit .213 in 28 games for San Francisco.

Williamson had a tough spring training and the Giants designated him for assignment as they broke camp. He accepted an assignment to Sacramento and began to gain notice with his hitting and defensive play. He was batting .378 with nine home runs, including three in a game Monday at Triple-A.

The Associated Press contributed to this report.