Lagares has a strained right intercostal muscle. Den Dekker started in center field Monday night and led off in the finale of a five-game series against the Philadelphia Phillies.
Lagares is hitting .288 with two homers and 18 RBIs. Den Dekker was 0 for 4 in three games with the Mets before being sent to Triple-A on Sunday.
Chris Young will split time with den Dekker in center while Lagares is out.