First baseman Nick Evans has been promoted from Triple-A Buffalo to take Wright's place on the 25-man roster.
"I was shocked by it," manager Terry Collins said Monday about the diagnosis. "... He is without a question the face of this team. His presence in this lineup is something we need. We're going to ask other guys to pick it up as of today. But I was shocked and unhappy."
Wright had an MRI on his ailing back on Monday at the Hospital for Special Surgery.
He also underwent a CT scan on Monday night, as the team sought a second opinion, which confirmed the results of the MRI.
Surgery will not be required.
Wright will have no baseball baseball activity for 10 days, and then be re-evaluated at the Hospital for Special Surgery before beginning baseball activity.
"I knew I did it on the Carlos Lee play at third base," Wright said Monday. "We were playing Houston at home. I don't know what the date was. About the first week, I felt stiff and sore, but I felt that would go away the next couple of weeks. I was on some medication and some anti-inflammatories that really wasn't doing much. That explains it now, because it's not a muscular thing.
"It's what could be a stress fracture. ... It's probably me somewhat being stubborn and not getting it checked out earlier. I don't think it really limited me too much or prohibited me from doing anything. It was just a little uncomfortable."
He last played on May 15 in Houston and went 0-for-3 with a walk.
This is the second time that Wright has been placed on the DL in his career (2009).
The 28-year-old is hitting just .226 with six homers and 18 RBIs, but wouldn't use the injury as an excuse for his recent struggles.
Since April 19 -- a span of 23 games -- Wright is hitting .205 (17-for-83) with seven extra-base hits.
"By no means is this thing a cop-out or an excuse for what I've done so far," Wright said. "I've played through it and when I take the field, I expect to play at a certain level, and thus far I haven't been able to play at that level.
"This two weeks, I'm going to get better. I'm going to get back in the lineup and I'm going to start playing at the level I expect."
The 25-year-old Evans compiled a .248 batting average with five home runs and 16 RBIs in 36 games for the Bisons.
He hit .306 (11-for-36) with one home run and five RBIs in 20 games with the Mets last season.
Mike Mazzeo is a regular contributor to ESPNNewYork.com.