SAN FRANCISCO -- Right-hander Trevor Rosenthal signed a $4.5 million, one-year contract with the San Francisco Giants on Thursday.

Rosenthal has a chance to pitch in the majors for the first time since 2020. He will be on the injured list with a hamstring strain initially, and manager Gabe Kapler said he's several weeks away from helping the team.

Kapler called Rosenthal "one of the more effective closers in the game. The talent hasn't gone anywhere. It's an electric arm."

He has the potential to earn an additional $1 million in performance bonuses for big league games pitched: $50,000 each for 15 and 18 games; $150,000 for 23 games; $200,000 for 28 games; $250,000 for 33 games; and $300,000 for 38 games pitched. In addition, Rosenthal also could make $1 million in performance bonuses for games finished: $100,000 for 12 games; $150,000 for 15; and $250,000 each for 18, 21 and 24 games.

The 32-year-old Rosenthal received an $11 million, one-year contract from Oakland before the 2021 season but never pitched. He had surgery for Thoracic Outlet Syndrome in April that year and underwent surgery for a torn right hip labrum last July.

Rosenthal went 1-0 with a 1.90 ERA with 11 saves over 23 2/3 innings for the Kansas City Royals and San Diego Padres in 2020.

The Giants released closer Jake McGee before the All-Star break.