NEW YORK -- Mets ace Jacob deGrom resumed playing catch and plans to evaluate his mechanics after New York placed him on the 10-day injured list Tuesday with tightness in his right side.

The two-time NL Cy Young Award winner was pulled from a game Sunday against Arizona, his first appearance after skipping a start due to discomfort in his right lat muscle. The 32-year-old got an MRI on Sunday night that showed no structural damage.

Mets manager Luis Rojas said the team was unsure how the issue arose for deGrom, who is 3-2 with a major league-best 0.68 ERA along with 65 strikeouts in 40 innings.

"The plan right now is to treat it because it's tightness and to make sure that when he's throwing, there's nothing getting out of whack because of the tightness," Rojas said.

DeGrom was uncharacteristically wild in the fifth inning Sunday, walking three batters in an inning for only the second time in his big league career. He threw two warm-up pitches ahead of the sixth inning before leaving the game after 68 pitches.

Rojas said deGrom's mechanics were off in the fifth, causing the right-hander to drop his arm angle, get under the ball and sail it high of his target. The Mets believes the delivery issues are tied to the tightness, and Rojas said deGrom willingly went on the IL in part because he wanted to correct that flaw.

Pitching coach Jeremy Hefner and others on New York's staff plan to closely monitor deGrom's motion as he plays catch the next few days. DeGrom will also get massages and other treatments on his side -- the tightness is centered near his lower-right back -- prior to playing catch.

"This is what happens sometimes when you're tight from a particular area," Rojas said. "You don't feel pain, but it really causes you to move differently, rotate, land, it causes a lot of things. You can lose your arm angle, and it can expose some things."

The Mets will have deGrom loosen and throw daily until he's ready for a bullpen session. Rojas was unsure if deGrom would return when he's eligible May 20.

DeGrom is baseball's hardest-throwing starting pitcher, with 79 pitches of 100 mph or higher since the start of the 2020 season, according to MLB Statcast. Miami's Sixto Sanchez in second with 13.

Of those, deGrom reached 100 mph 42 times in the first inning alone. Sanchez is second with eight.

Right-hander Sean Reid-Foley was recalled from Triple-A Syracuse, but Rojas said the team hadn't decided how to fill deGrom's vacated rotation spot. The Mets are off the next two Thursdays, meaning they could proceed with a four-man rotation.

The news on deGrom comes as the Mets are in their best stretch of a topsy-turvy season. They take a five-game winning streak into Tuesday's game, and are in first place in the National League East.

The Associated Press contributed to this report.