The Padres selected Johnson's contract from Triple-A El Paso on Monday, and he will start in right field and bat ninth for Monday's series opener against the Nationals.
Johnson's promotion to the big club was part of a flurry of moves made by the Padres on Monday, including the placement of Fernando Tatis (quadriceps) on the injured list. Johnson joined San Diego on a minor-league contract in December, and in Triple-A he's slashing .301/.430/.461 with three home runs and 28 RBI over 259 plate appearances while adding 18 stolen bases. He appeared in 30 major-league games with the Giants in 2023, and the 28-year-old will be thrown into big-league action Monday against Nationals right-hander Patrick Corbin.