PEORIA, Ariz. -- Seattle Mariners right-hander George Kirby has inflammation in his throwing shoulder and likely will open the season on the injured list.

"I would not anticipate that he's ready for the first 10 days, two weeks of the season," Mariners general manager Justin Hollander said Friday.

Hollander emphasized that an MRI revealed no structural damage to the shoulder.

Although Hollander said Kirby has been throwing the ball well with a velocity that met expectations, the right-hander hadn't felt he was bouncing back from each outing particularly well. That led to the MRI.

Hollander said the Mariners plan to shut Kirby down to get the inflammation out. He will be reassessed in a week.

"We want to make sure we're doing the right thing for the big picture of the whole season as opposed to worrying about Opening Day," Hollander said.

Kirby, 27, started 33 games last season to tie for the major league lead. He went 14-11 with a 3.53 ERA with 179 strikeouts and 23 walks in 181 innings.

He made the AL All-Star team in 2023, when he made 31 starts and went 13-10 with a 3.35 ERA.