SAN DIEGO -- New York Mets catcher John Buck is getting an addition to the family. And top catching prospect Travis d'Arnaud is getting to make his major league debut as a result -- and perhaps will stick with the big-league club for good.

Buck was scratched from Friday's starting lineup after his wife, Brooke, went into labor in New York, the Mets announced. The couple had been expecting the baby boy Aug. 1.

The veteran catcher will be placed on paternity leave Saturday for three days, through the Mets' makeup game Monday against the Twins in Minnesota. Buck then would be reactivated for Tuesday's homestand opener in New York.

D'Arnaud, meanwhile, will be called up to fill in for Buck. But with the top catching prospect's Triple-A Las Vegas team in Salt Lake City on Friday, d'Arnaud was unable to get to Petco Park in time for Friday night's game against the San Diego Padres. Anthony Recker replaced Buck in the starting lineup.

Mets general manager Sandy Alderson indicated d'Arnaud will have a chance to stick at the major-league level if he performs well during the three-day audition. Otherwise, he would return after major-league rosters expand in September.

"We're realistic, and this just could be a three-day stint, although September is just around the corner," Alderson said. "And I would certainly expect that even if he does go back to Vegas, he will be with us in September."

Outfielder Andrew Brown served as the Mets' backup catcher Friday night. Brown has been carrying catching equipment for a week. He said he caught at Class A, although he never appeared in an official game.

Alderson also announced that right-hander Jeremy Hefner, on the disabled list with an MCL strain in his right elbow, will get another opinion on the injury Monday. Hefner may require Tommy John surgery.

D'Arnaud, 24, was acquired from the Toronto Blue Jays with fellow prospects Noah Syndergaard and Wuilmer Becerra in December for reigning NL Cy Young winner R.A. Dickey. Buck also was part of that trade, in a swap of catchers, for Josh Thole and Mike Nickeas.

D'Arnaud suffered a broken first metatarsal in his left foot on April 17, when he was struck with a foul ball while catching for Las Vegas. He returned to game action July 24 in the Gulf Coast League, advanced to Double-A Binghamton a week later, and has been back in Triple-A for seven games

D'Arnaud is 8-for-20 with one homer, four RBIs and nine walks since rejoining Las Vegas.

"I know John's baby was supposed to be born Aug. 1 or something like that," d'Arnaud told ESPNNewYork.com on Wednesday. "[The delay has] given me time to hone my skills and feel a lot more comfortable behind the plate, and when I'm hitting, too. I just didn't have my timing and was trying to do too much. I finally got my game back and my approach back the last two weeks."

Added Alderson: "It will be nice to see him in a New York Mets uniform. There's been a lot of anticipation, and some disappointment given the injury that he sustained early in the year -- more disappointment on his part than probably anyone else's."

D'Arnaud would have enjoyed making his major league debut at Dodger Stadium, the Mets' previous stop on this road trip, but elsewhere in Southern California undoubtedly will do. D'Arnaud grew up in in Lakewood, Calif., some 20 minutes from the L.A. ballpark. He attended two or three Dodgers games a month as a youngster, cheering for favorite players Mike Piazza and Russell Martin.

"That would have been the dream," d'Arnaud said of debuting in L.A. "That's for sure."

As for the length of time it took for him to return from the broken foot, d'Arnaud said: "At first they said -- what? -- six to eight weeks. And I think it took an extra month. I guess it's a good thing to make sure it's healed 100 percent. I didn't really stress out about it. It's just the Mets' plan and God's plan."

Mets officials had suggested d'Arnaud had foot discomfort when he started running on flat ground not long after finally getting to shed a protective boot June 10. But d'Arnaud minimized that issue.

"That first day running on land it just felt like you hadn't ran in two months," d'Arnaud said. "I felt like it was normal, and so did they. So we just kept the progression going."