Sandy Alderson said Saturday that it was unusual for a player to refuse an MRI, as Noah Syndergaard did Friday, but said, "I can't strap him down and throw him in the tube."

Syndergaard is scheduled to start for the New York Mets on Sunday after he was pulled from his start Thursday because of biceps and shoulder discomfort.

Syndergaard is 1-1 with a 1.73 ERA in four starts.

"I think I know my body best," Syndergaard told reporters. "I'm pretty in tune with my body, and that's exactly why I refused to take the MRI."

Noah Syndergaard has been terrific through his first four starts this season, pitching to a 1.73 ERA and 30 strikeouts in 26 innings.

The New York Mets right-hander's average fastball velocity is 99.6 mph, but it is his control that has him chasing history.

He has yet to walk a batter in 2017 and only 16 pitchers (12 starters) have opened a season with more walk-less innings.

Syndergaard is scheduled to start on Wednesday against the Atlanta Braves and with seven innings pitched without a walk, he would move into a tie for second-place on the all-time list. The leader, Pete Alexander of the Chicago Cubs, tossed 51 innings to begin the 1923 season without issuing a walk.

Yoenis Cespedes was again held out of the New York Mets' lineup on Sunday because of a hamstring injury, with manager Terry Collins acknowledging the possibility the slugger could be headed to the disabled list if he's not fit to play by Tuesday.

"I think we'd need to take a look at that," Collins said before Sunday's game against the Nationals when asked if he would consider a DL stint for either Cespedes or catcher Travis d'Arnaud, who is nursing a wrist injury.

According to the Mets manager, Cespedes, who has now missed three straight games, "told me he felt a lot better today." Collins is hopeful the outfielder will return for New York's series opener against the Braves on Tuesday.

Stephen Strasburg will not take his regular turn in the Nationals' rotation this week as he awaits the birth of his second child.

The Nationals plan to put Strasburg on the paternity list Monday, when they open a four-game series in Colorado. The team has not announced a scheduled starter for that game.

Strasburg's next turn comes up Tuesday, but Washington bumped back Joe Ross a day into that slot. The team said Sunday that Strasburg could pitch next weekend at home against the Mets.

With Jose Reyes enduring a slow start to the season, Terry Collins jokingly called for a national search to find the four-time All-Star.

"I've got the FBI out looking for the real Jose Reyes," Collins said. "He's being held someplace."

Reyes was 1-for-27 (.037) entering Tuesday's game. He went 1-for-6 against the Philadelphia Phillies.

"You have to let him work through it,'' the New York Mets manager said. "... We all know he's just too good a player to continue to struggle, and I think when he breaks out you're going to see a different lineup."

David Wright has been cleared to resume throwing, but for now he's just throwing softly in an effort to slowly build up arm strength.

Wright was forced to stop throwing with no clear timetable to resume more than a month ago. He had been able to swing the bat all spring, but was having issues with throwing.

The New York Mets third baseman had been working on strengthening his impinged shoulder.

Steven Matz revealed that he's been suffering from a strained flexor tendon, but New York Mets have been asking who made the diagnosis.

"Our [doctors] found nothing wrong," said one source with knowledge of Matz's care.

The Mets don't know what's wrong with Matz and when he'll be able to pitch again.

Matz has reported discomfort in his pitching elbow despite an MRI showing no damage.

Tim Tebow homered for the second time in three games Sunday as he completed his first series with the New York Mets' Class A affiliate, the Columbia Fireflies.

The former quarterback hit a two-run home run in his first plate appearance Thursday night, then followed that with a three-run shot to right field on Sunday as the Fireflies beat the Augusta GreenJackets 6-0.

Tim Tebow hit a two-run home run in his first at-bat in his debut for the Class A Columbia Fireflies on Thursday.

"All of my sports experiences helped me for moments like that," Tebow said. "Playing in The Swamp or Death Valley or in Mile High Stadium in the playoffs, they all helped.

"So much about sports is handling moments and handling pressure."

Tebow drilled a 2-1 pitch off the railing in left-center field, where a strong wind had been blowing out all day.

His only mistake was that he initially thought it was a ground-rule double, because the ball ricocheted back onto the field, and stopped at second.

Tebow later had a weak groundout to shortstop and struck out in his next three at-bats -- twice looking and then swinging in his final at-bat.

The New York Mets have signed Desmond Jennings to a Minor League contract.

Jennings has been assigned to Triple-A Las Vegas.

He spent spring training with the Cincinnati Reds but was released recently.