The New York Mets optioned right-hander Kodai Senga to Triple-A Syracuse after a string of poor outings, the team said Friday, a move that required the pitcher's consent under his contract.

Senga, 32, has endured a rocky stretch since returning from a right hamstring strain in mid-July, posting a 6.56 ERA over his last eight starts.

An All-Star and runner-up for National League Rookie of the Year in 2023, Senga is in the third season of a five-year, $75 million deal. He owns a 7-6 record and 3.02 ERA across 22 appearances this year. Mets manager Carlos Mendoza said the focus was on "getting him right" amid the late-season playoff race.

To replace Senga, New York plans to call up the team's No. 5 prospect, right-hander Brandon Sproat, to start Sunday against Cincinnati. The move will leave three rookies -- Sproat, Nolan McLean and Jonah Tong -- in the Mets' six-man rotation.

The Mets also activated catcher Francisco Alvarez, who will attempt to finish the season while managing a torn thumb ligament and fractured finger, and added reliever Wander Suero after claiming him from Atlanta. To round out the moves, catcher Hayden Senger (.174 in 30 games) was optioned to Syracuse along with Senga. Right-handed reliever Reed Garrett was sent on a rehab assignment to Double-A Binghamton on Thursday.

Alvarez, 23, is batting .265 with seven homers and 24 RBIs in 56 games this season.