Will Middlebrooks is congratulated by Jarrod Saltalamacchia (39) as Ryan Kalish looks on Thursday. (AP)

The more Daniel Nava and Ryan Kalish succeed, the more Red Sox fans are intrigued. After all, it’s easy to get caught up in Nava’s numbers, which include a .439 average in 14 June games including six multi-hit games that has him hitting .340 in 35 games overall. It’s easy to see Kalish race from first to third on a hit-and-run grounder off the bat of Mike Aviles in the eighth inning and say the Red Sox need that energy.

And it’s easy to wonder why – when Nava drives in Kalish with the go-ahead run on a broken bat single – both can’t stay with the Red Sox long term.

That’s not even mentioning Will Middlebrooks, who appears closer and closer to a full-time job as the Red Sox starting third baseman.

But with Nava and Kalish, it’s fascinating because of what is waiting in the wings several weeks down the road with Carl Crawford and Jacoby Ellsbury. Both are getting ready for game activity as part of their rehab programs, including Crawford on Saturday in Florida.

“I’ve been aware of it since I got called up and so I know it’s a reality,” Nava said after driving in the winning run in Boston’s 6-5 win over the Marlins. “It was a reality the last time I got called up. But if there’s anything I can do to help the team get back to where we’re hanging in there, those guys come back and have a shot, who knows where it’s going to go. I’m aware of it. I think anyone who gets called up and doesn’t have a big contract, it’s a reality.”

The reality is that left fielder Carl Crawford has yet to play a game in the second season of a seven-year, $142 million deal. The reality is that Jacoby Ellsbury is an All-Star caliber center fielder who finished just behind Justin Verlander in the American League MVP voting in 2011 and is making $8 million this season.

Nava, on the other hand, was signed to a minor league deal before spring training after making $417,500 in 2011. Kalish isn’t far behind. He’s making $483,000 this season. It’s assumed that one or both will head back to Triple-A Pawtucket when Crawford and Ellsbury return.

“Those decisions aren’t mine to make,” Nava said. “It can’t hurt but at the same time it’s not about me trying to put a feather in my cap. It’s about me trying to say, ‘Hey, this is something I did to help the team win’ and get in the right direction. They’ll make the decisions they have to make and whatever they think will help the team is what they’re going to do.”

“It’s awesome,” Kalish said of Nava and Middlebrooks. “They’ve been here a while and they’ve been doing since the day they got here. As young guys, that’s all you want to do, you want to bring fire and spark people.”

Never was that spark more evident than when Kalish went first-to-third on a hit-and-run grounder by Mike Aviles to the second baseman to set up the game-winning run in the eighth.

“If I don’t feel that true aggressive feeling of no regrets, then I’m not going to try it,” Kalish said. “But on that play, I felt really confident about it.”

Nava and Kalish’s teammates appreciate their hustle.

“We need it,” Cody Ross offered. “We need energy. I know in the past, we’ve relied on the three-run homer. We’ll still hit those, too, but to see guys go first-to-third like Kalish did and Nava not trying to do too much, just putting the bat on the ball. Then Will coming up with some big hits, too. Just a great win.”

Another irony to Thursday’s win – the 29-year-old Nava is older than Dustin Pedroia by nearly six months. So when asked what it’s like to be part of the young group of players contributing to the team’s success, Nava was pleasantly surprised.

“I’m considered young? That’s awesome,” he said with a wide smile.

“It was a huge play by Kalish to get on the hit-and-run first-to-third. It changed the whole dynamic of the last at-bat. Obviously, the last at-bat doesn’t mean anything unless Will does what he does.”

Asked what he thought of Boston’s “young guns” Jarrod Saltalamacchia asked for clarification. Told they were the trio of Kalish, Middlebrooks and Nava, Saltalamacchia expanded.

“OK, we’ve got the ‘Young Guns’ then. Everyone’s picked up. We’ve got guys injured and been out. Nava’s done an unbelievable job, doing a great job in the leadoff spot, got a big hit tonight. Obviously, Will’s doing the same. It’s tough. We have such a good lineup. It’s tough. We have such a good lineup, and we have guys on the bench who can do the same. It’s tough to get to get everyone in the lineup and sometimes, like it’s been, [Adrian Gonzalez] has to play right just to get everyone in there because we are that good.”

And the Red Sox won’t mind at all if those decisions just keep getting tougher.