New York Mets' Jay Bruce is greeted by Neil Walker...

New York Mets' Jay Bruce is greeted by Neil Walker after hitting a home run in the first inning of a baseball game against the Pittsburgh Pirates, Saturday, May 27, 2017, in Pittsburgh. Credit: AP / Keith Srakocic

Jay Bruce and Neil Walker have become de facto captains of the Mets during the prolonged absence of David Wright. Both have become go-to players for an accurate assessment of the team. Soon the pending free agents may be contemplating their own futures.

With the Mets 11 1⁄2 games behind the NL East-leading Nationals and eight out in the wild-card race, the buyer-seller debate is not far off as the July 31 non-waiver deadline approaches.

On Monday, general manager Sandy Alderson left for Salt Lake City to take a hard look at top prospect Amed Rosario, 21, whose days as a Triple-A player for Las Vegas may be ending. Rosario went 1-for-4 with his 40th RBI on Monday night and is hitting .345.

The arrival of the Mets’ top prospect would have some immediate ramifications. Rosario likely would supplant suddenly error-prone Asdrubal Cabrera at shortstop. The Mets are paying Cabrera $8.25 million this season but can buy him out for $2 million in 2018, according to Spotrac, which tracks player contracts.

The addition of Rosario could either light a spark or put other players on notice. In addition to Bruce and Walker, Lucas Duda, Curtis Granderson and Addison Reed are the prominent free agents on the Mets’ roster.

“We’re certainly aware of the contractual status of the players that we have,’’ Alderson told a forum of season-ticket holders Sunday. “And interestingly, I think the players that we have are aware of Rosario’s performance . . . We just have to see how things play out. Not only with him and how he performs but also what happens here in New York.’’

The Mets obtained Bruce from the Reds at last season’s trade deadline, and after he struggled in the final two months of 2016, they picked up his $13-million contract for 2017 with the intention of trading him last offseason. It didn’t happen, and now he is having a good season with 13 homers, 36 RBIs and a .495 slugging percentage in 52 games.

Bruce hopes to stay beyond this season. “I’ve enjoyed my time here,’’ he said. “My career here didn’t start necessarily how I wanted it to, but I’ve been welcomed by the organization. It’s a very passionate fan base and a team that I think has a lot of talent and a lot of ability, so yeah, I would consider myself a needed commodity.

“I think I’m an impact player. I think I can help the team in a positive way. I take a lot of pride in offense and defense. I take a lot of pride in staying on the field. I take a lot of pride in kind of staying under the radar, just doing my job . . . The more guys like that that you can have, the better.’’

Walker became the replacement at second base in 2016 after free agent Daniel Murphy left for the Nationals. Walker had back surgery last September and in November accepted a qualifying offer of $17.2 million for 2017. He appeared close to signing a contract extension in spring training, but talks ended with no deal. He also wants to remain but said: “I’m going to have hopefully a lot of options. We’ll see. We obviously almost got something done here in spring training and that didn’t happen.

“I’m not disappointed in the team, but I’m disappointed kind of in the process of things. I guess that’s business. Sometimes things go the way that you hope and sometimes they don’t. I’m going to play this year, I’m going to see how things go. And I can take a bird’s-eye view when the season ends of what’s out there.’’