ATLANTA -- The New York Mets added right-hander Taijuan Walker to their lengthy injured list on Wednesday after he lasted only three innings in this week's start against the Braves due to tightness in his left side.

In a related move, the Mets selected the contract of outfielder Cameron Maybin from Triple-A Syracuse and started him in left field in Wednesday night's game against the Atlanta Braves. The Mets acquired Maybin from the Chicago Cubs on Tuesday for cash.

Walker was placed on the 10-day injured list, retroactive to Tuesday. Left-hander Stephen Tarpley and right-hander Sam McWilliams also were placed on the injured list.

Mets manager Luis Rojas said the plan for Walker is similar to the schedule for Jacob deGrom, who is on the 10-day IL with tightness in his lower back.

Rojas said deGrom will have an injury rehabilitation start with Class A St. Lucie on Thursday. The team wants to see deGrom avoid a recurrence of the discomfort in his back while pitching in a game.

"We want to see him facing batters, ramp up the competition level," Rojas said.

On Tuesday, the Mets said Walker's MRI showed no structural problem. Rojas said the Mets "want to see the mechanics" when Walker pitches. Rojas said Walker's difficulty may be related to his windup and delivery.

The 34-year-old Maybin had hit .103 with one homer and three RBIs in 10 games and 43 plate appearances with Triple-A Iowa this season.

New York's injured list includes outfielders Michael Conforto (hamstring), Brandon Nimmo (finger bone bruise), Albert Almora Jr. (bruised left shoulder), and Kevin Pillar (facial fractures).

Second baseman Jeff McNeil also was placed on the 10-day IL with a hamstring injury on Tuesday.