NEW YORK -- As the Mets got one of their big names back, they lost another.

New York activated Robinson Canó (left quad) from the injured list Sunday, and the second baseman went 1-for-3 with a walk and a double out of the No. 5 spot in New York's 4-3 loss to the Cardinals. But adding Cano to the roster came with the loss of Noah Syndergaard, whose right hamstring strain sustained in Saturday night's start has forced him to the IL. He'll miss at least one start.

Syndergaard went for an MRI on Sunday morning, but manager Mickey Callaway said after the game that the Mets don't yet have the results and diagnosis. Syndergaard, who wasn't available for comment pregame, was briefly in the Mets' clubhouse postgame, but he only said, "It's very mild" before leaving.

The Mets said the next official update on Syndergaard's condition will come on Monday.

Manager Mickey Callaway said Sunday that the Mets haven't yet decided who will replace Syndergaard in the rotation, but he said that Anthony Kay, the team's No. 7 prospect who was promoted to Triple-A this week, likely won't be considered for the spot.

"Probably not at this point," Callaway said. "We'll probably throw his name around, we'll see -- we haven't really gotten to that point [of discussions]. But I think that Anthony probably needs a little more time. But I would say that his name might get thrown in the mix."

If not Kay, the Mets could turn to someone like Walker Lockett, who has a 3.28 ERA in four games for Triple-A Syracuse this season, or even Seth Lugo, who has started in the past. New York's starting pitching options are thin with Chris Flexen recently converted to relief, Hector Santiago designated for assignment and Corey Oswalt on the IL at Triple-A.

Syndergaard limped off the field in the seventh inning Saturday, after grabbing at his right leg as he moved off the mound during a stolen base attempt. After that play was complete, Syndergaard motioned to Callaway in the dugout to come out to the mound, and he left the game after speaking with Callaway and trainer Brian Chicklo.

The 26-year-old spent time on the injured list twice in 2018, with a strained ligament in his right index finger and then with an infection. He missed the majority of the 2017 season with a torn right lat. He hasn’t dealt with any hamstring issues in the past of note, and none that sent him to the IL.

As for Cano, Callaway said the Mets will manage his playing time as he works his way back into game action. Cano's latest IL stint came after he re-injured himself in his first game back from a left quad strain originally suffered in late May.

"We're doing something a little special with [Jeff] McNeil. … We've been giving him off the day games after night games, things like that. We'll probably take a similar approach with Robbie," Callaway said. "We have a lot of games in a row, and we'll manage his workload appropriately."

McNeil has been one of the Mets' best hitters -- he was batting .335/.406/.459 entering Sunday -- and his best defensive position is second base. The 36-year-old Cano has struggled at the plate this season, hitting .238/.284/.366 through 46 games prior to his injury. But Callaway said when Cano is in the lineup, he's still the Mets' second baseman.

"We'll monitor his workload, but when he plays he's gonna play second. That's about as simple as I can put it," Callaway said. "We'll see moving forward, but like I said, we'll monitor his workload to make sure we can keep him as healthy as possible."

Cano said that he came through Sunday's game fine -- he had a chance to test his quad legging out his third-inning double, and he also scored from second on Adeiny Hechavarria's RBI single.

"It went well," Cano said. "It feels good. I was able to hit the double and score, and that tells me how good I feel, being able to score in that situation."

But he hasn't yet talked to Callaway about the workload management.

"Whatever it is," Cano said, "I've just got to stay healthy and be able to stay out there and help the team win games."

Nimmo getting further evaluation

Outfielder Brandon Nimmo (bulging cervical disc) is still dealing with the same neck issue that's plagued him since April, and the Mets are sending him to see more specialists, Callaway said Sunday.

Mets sign three more Draft picks

The Mets announced the signing of three more 2019 Draft picks on Sunday -- outfielders Kennie Taylor (14th round, Duke), Tanner Murphy (18th round, North Florida) and Cole Kleszcz (33rd round, Azusa Pacific). They've now signed 22 of their Draft picks, including first-rounder Brett Baty.