The New York Yankees are shutting down first baseman Anthony Rizzo for the rest of the 2023 MLB season, team manager Aaron Boone told reporters on Tuesday.

The 34-year-old has been placed on the injured list since August 3, and he has not seen action in over a month due to post-concussion syndrome.

"I would say everything is going well. His most recent checkup was all the things we're looking for as far as his improvements," Boone said.

Doctors expect Rizzo to be healthy for the 2024 season as Rizzo is "continuing to make all the right cognitive improvements."

Rizzo recently signed a two-year contract with the Yankees in November 2022, with a club option available for the 2025 season. The four-time Golden Glove award winner is set to earn $17 million next year.

Concussion stems from an incident three months ago

The 2016 World Series winner collided with shortstop Fernando Tatis Jr. during a Yankees game against the San Diego Padres over three months ago on May 28.

He initially passed the MLB's concussion protocol but started feeling unwell over the next few months.

Rizzo would wake up feeling hungover without taking alcohol, and his brain felt hazy at times, according to the New York Post.

The effects of the concussion carried over on the baseball field, wherein he would have slower reaction times and miss pitches that he mostly hit over a 13-season career in the major leagues.