COSTA MESA, Calif. (AP) — Justin Herbert will undergo surgery on Tuesday on his broken index finger on his right hand and will miss the Los Angeles Chargers’ remaining four games this season.

Herbert visited two hand specialists on Monday after he suffered the injury during the second quarter of Los Angeles’ 24-7 loss to the Denver Broncos on Sunday.

“He is tough as they come, but we’re going to make sure that, whatever it is, we’re going to do what is best for Justin, long term,” coach Brandon Staley said on Monday.

Herbert is the seventh starting quarterback in the league to be lost for the season because of an injury if the Jets’ Aaron Rodgers does not return from his torn Achilles tendon. That includes the top two QBs who signed extensions during the preseason.

Herbert signed a $252.5 million extension on the first day of training camp and Cincinnati’s Joe Burrow inked a five-year extension worth $275 million three days before the start of the regular season.

Easton Stick will get his first NFL start on Thursday night at Las Vegas against the Raiders. The Chargers are 5-8 and have dropped four of their past five.

Stick will be only the fourth Chargers starting quarterback since 2006, which is tied with Tampa Bay and Philadelphia for second fewest in that span.

Green Bay and Seattle have had only three starting QBs in the past 18 seasons.

Herbert, the sixth overall pick in the 2020 draft, had been durable in his career, with 62 consecutive regular-season starts. He has played through a broken finger on his non-throwing hand earlier this season and fractured rib cartilage last season.

Max Duggan, who was selected in the seventh round of April’s draft, will be called up from the practice squad to be Stick’s backup.