BALTIMORE -- Jonathan Papelbon threw his last pitch for the Boston Red Sox in this very ballpark. It was a splitter, and then-Baltimore Orioles infielder Robert Andino lined it to left field for an RBI single that knocked Boston out of playoff contention in the final inning of the last game of the 2011 season.

Five years later, it would seem fitting that Papelbon would return to the Red Sox during another trip to Camden Yards.

If manager John Farrell has his way, it might just happen. Farrell acknowledged Tuesday that he has contacted Papelbon, who requested and received his release from the Washington Nationals last Saturday and reportedly expects to sign with a new team by Wednesday. Farrell said the Red Sox have had "internal discussions" about bringing back their all-time saves leader, but that he has reached out to Papelbon is a not-so-subtle sign that the club has genuine interest in a reunion.

"With the exception of a stretch in July, where maybe the performance was less than what Pap has been maybe accustomed to, he's been an effective pitcher," Farrell said. "Coming back to Boston, if that were to happen, he's very well aware of the environment, the expectation. So we'll see where that goes."

If Papelbon signs with the Red Sox, he wouldn't be used as a closer. Not with Craig Kimbrel entrenched in the ninth-inning role. But the Sox have been seeking a primary eighth-inning setup man ever since Koji Uehara was sidelined indefinitely last month by a strained right pectoral muscle.

Papelbon posted a 4.37 ERA and 7.97 strikeouts per nine innings for the Nationals this season, far off his career totals of 2.44 and 10.02. But he also had a 2.56 ERA as recently as July 23; his numbers were inflated by the five-outing stretch that followed, in which he gave up eight earned runs on nine hits and five walks in 3 1/3 innings.

That slide led the Nationals to make a deal for All-Star closer Mark Melancon at the trade deadline. One National League talent evaluator described Papelbon's attitude as "toxic" and said it was "an easy decision" for the Nationals to let him walk last weekend, even though they owe him the balance of his $11 million salary.

Papelbon has been a lightning rod since he left Boston. He had a tumultuous relationship with teammates and fans during parts of four seasons with the Philadelphia Phillies and had a physical confrontation with Nationals star Bryce Harper in the dugout last season.

But the Red Sox might be the one team that isn't concerned about Papelbon's makeup. He grew up in the organization and was in the big leagues when general manager Mike Hazen was still the farm director. And Papelbon remains close with team leaders David Ortiz and Dustin Pedroia, as well as right-hander Clay Buchholz. The four were teammates on the club that won the 2007 World Series.

"He's still got a big name here," Buchholz told ESPN.com Tuesday before the Red Sox opened a two-game series against the Orioles. "Everybody knows what he's done in the past and helped us with the World Series in '07. He's high-energy, everybody knows that. He's not afraid to speak his mind. That helps through a lot of situations, too, especially with the young guys that we have now. I think it would be a neat experience for everybody in here."

The bigger question for the Red Sox is whether Papelbon can still pitch. His average fastball velocity has declined from 95.0 mph when he left the Red Sox after the 2011 season to 90.9 mph with the Nationals this year. Likewise, his strikeouts per nine innings have decreased from 12.17 in 2011 to 7.97 this season.

"Even with his velocity and everything that has sort of declined a little bit, I think he's learned how to pitch with the stuff that he's got," Buchholz said. "He's still good at what he does."

If that's the case, Papelbon could help make Farrell's job easier. Farrell has been mixing and matching in the seventh and eighth innings, using a combination of right-handers Brad Ziegler and Junichi Tazawa and lefties Fernando Abad and Robbie Ross Jr. An effective Papelbon would help define the roles at the back of the bullpen, something Ortiz said after Monday's 3-2 victory in Cleveland will be essential to the Red Sox winning more low-scoring games.

"Every ballclub wants to have the seventh-, eighth- and ninth-inning pitchers, so when they get to that position, boom, here we go," Ortiz said. "We're trying to locate ourselves in that position."

One thing is clear: The Red Sox will be waiting for Papelbon to make his decision.

"Pap is a unique guy in many ways, but a guy that thrives in the moment, thrives to be in critical spots in the ballgame," Farrell said. "While that closing role may be a thing behind him, still, the intangibles of the competitor haven't changed."