Terry Francona gives Nick Green a congratulatory pat on the head after Green's walk-off home run on Sunday.

Journal photo / Mary Murphy

BOSTON -- Nick Green came into spring training with something to prove. After a lousy 2008 season spent entirely in the minor leagues, he needed to show baseball, and to show himself, that he was bigger than that. He was a man who could help a major league ballclub, and could be counted on to play every day.

"That was my goal out of spring training -- to get an opportunity to play, and prove to people that I can play, and prove that last year was a fluke," the 30-year-old Green said.

He's done that, and more. On the way to proving that he can play, Green has shown that he deserves a better label than the one he's long worn: career utility infielder. He's good enough to succeed at shortstop on the best team in the American League, on one of the biggest stages in baseball. And he's not done yet, he said.

"Did I have something to prove? Yes, I did. And I still have something to prove," Green said.

He proved Sunday that he can deliver in the clutch, hitting a home run to right field in the bottom of the ninth inning to give Boston a 6-5 victory over Green's former team, the Atlanta Braves. Green's only other walk-off home run came when he was with Atlanta, in July of 2004 -- off Red Sox pitcher Anastacio Martinez.

Green came into spring training as a non-roster invitee, with little chance to make the major league club. Coming off a disappointing 2008 spent entirely in the Yankees' minor-league system, Green arrived at Red Sox camp in excellent shape, and with a modified swing. Green told The Journal last week that much of his success came from working out with his former Braves teammates in the offseason, and by incorporating the toe-tap they practice into his own swing.

An injury to shortstop Julio Lugo gave Green a chance to show what he could do during spring training, and he took it, posting excellent numbers and exhibiting a powerful arm. It was a stressful situation, but he made the most of it, manager Terry Francona said.

"Guys are getting ready for the season, but he's trying to fight for his baseball life," Francona said.

Green's natural position was second base, not shortstop, but he showed that he could handle it well enough that Boston put him on the major league roster to start the year, backing up Jed Lowrie at short.

Then Lowrie went down himself, undergoing wrist surgery, and Green stepped into a starting role.

He initially struggled in the field, notably air-mailing one throw in Seattle that cost the Sox the game. But his defense has improved significantly, and after compiling eight errors through April and May, he has only one in June, in more playing time.

"I think I've matured enough as a shortstop -- every day they put me in there, I gain more confidence. If [Francona] has confidence in me, I'm going to play better, and if he does, it makes me feel good too," Green said.

Green has been with five organizations over six years, but succeeding on such a big stage has helped Green start to shed the dreaded role-player label.

"He's one of those guys who I think, early on, got one of those utility player labels. But some things happened, he got his shot and he ran with it. And it couldn't have happened to a better guy," teammate Jason Bay said.

Francona agreed. As nice a story as Green is, it's even nicer to realize that he's not just playing well for who he is and where he came from. He's playing well, period.

"It's gotten to the point where he's just been a really good player, not a really good non-roster player, a really good major league player," Francona said.

For Green, this experience has been everything he'd hoped for and more.

"It's been a blast... it's one of those things where you actually enjoy coming to the park. I'd rather actually come to the park than sit at home on an off-day, because I don't have anything to do," he said.

dbarbari@projo.com