Mariners Successfully Challenge Shift Rule Violation vs. Royals, Awarded 1st Base

The Seattle Mariners are sticklers for the new shift rule.

As the Mariners faced he Kansas City Royals on Thursday, Royals’ second baseman Michael Massey lined up with his heels slightly touching the outfield grass, which is technically illegal with the new rule implemented this season.

The Mariners than challenge a routine ground out, and they were successful, meaning Dominic Canzone was safe at first. Two at-bats later, he came in to score.

Andy Bissell, the Mariners’ replay coordinator, said they had noticed Massey’s heels hitting the outfield grass in previous innings, and finally got the chance to use the challenge when the ball was hit his way.

“It’s something we look for all the time,” he said. “Honestly, it’s usually the second baseman. Just depends on where the cameras are pointing. Kind of saw it earlier in the game, there was a few where he was getting close and a few where he was in the grass and the ball just wasn’t hit to him… Sure enough, Canzone hit the ball to him and there was just enough evidence to show that his heel was in the grass.”

MLB implemented the new shift rule ahead of the 2025 season, and it’s a slight tweak of an already-existing shift rule. Along with the defensive team having no more than two infielders on either side of second base before a pitch his thrown, all infielders must stand in the infield dirt and may not cross into the outfield before the pitch.

The second part of the rule is essentially to prevent infielders from playing in the shallow outfield.

Before this season, violating the rule meant the batting team could either accept the result of the play or be granted a ball. Now, the batting team can either accept the result of the play or take a free base, and the Mariners obviously chose the latter.

The successful challenge helped the Mariners win the game 2-0, and the victory put Seattle in a tie for the top spot in the American League West.