He officially is with the major league club for three days, while veteran catcher John Buck is on paternity leave. But Mets manager Terry Collins reiterated Saturday that d'Arnaud should remain with the major league club once Buck returns and not be returned to Triple-A Las Vegas assuming he demonstrates competency during this three-day audition.
Buck's wife, Brooke, gave birth to the couple's third child, Bentley Ryan Buck, Saturday in New York.
"We're certainly hoping he stays," Collins said about d'Arnaud. "Now is that a plan going in? No. But you've just got to hope that he's ready to show us he belongs here. I think the next three days we'll get a feel for where he's at, what we need to do and where we are with his development."
D'Arnaud becomes the sixth Mets rookie to make his major league debut this season, joining right-handers Zack Wheeler and Gonzalez Germen, left-hander Scott Rice, infielder Wilmer Flores and outfielder Juan Lagares.
D'Arnaud suffered a broken first metatarsal in his left foot while catching with Las Vegas on April 17 and only returned to the Pacific Coast League club on Aug 9.
He had missed the final two-and-a-half months of the 2012 season in Triple-A with a partially torn posterior cruciate ligament in his left knee after getting injured sliding into second base.
"My foot feels back to normal, like it was in April," he said. "It feels good. I don't even notice it all anymore."
The Bucks had been expecting the newborn on Aug. 1, and d'Arnaud was aware he was the likely call-up since then.
On waiting for two weeks for the birth and the promotion, d'Arnaud said: "I was trying not to think about it too much -- just trying to enjoy where I was and enjoy playing baseball."
Because d'Arnaud is new to the organization, aside from his experience in spring training catching the major league staff, he received a crash course Saturday after arriving from Salt Lake City, where the Mets Triple-A affiliate was playing.
"Today, I've already had conversations with all of them," d'Arnaud said about the starting pitchers. "Obviously, I've got a lot more conversations to make, and ask them how they've been feeling, and what their comfort level is, and what signs they want with runners on second -- just everything.
"I've already talked to [catching instructor] Bob Geren, and he's helped me out a lot, too. I know the Mets put together a good scouting report. I'm going to have a look at it and we're going to make a game plan and be ready for the game tonight."
"I was a huge Dodgers fan growing up," he said. "Watching those two guys catch, I tried to pretty much copycat them and do everything the way they do."
His family is en route to San Diego for his debut, with two years of injuries behind him.
"I just try to think, 'I'm here now,' and make the most of it and soak it all in," d'Arnaud said.