CHICAGO -- One of the best plays Travis Shaw has made so far this season was the type of play he’s had to work hardest to master.

Jacoby Ellsbury was on third base for the New York Yankees on a rainy Sunday night when Alex Rodriguez chopped a ground ball that took Shaw into foul territory down the third-base line. Shaw backhanded the ball out of the air and made a quick enough transfer and a strong enough throw to cut down the speedy Ellsbury at the plate by several steps.

It was a good play for any third baseman. It was a remarkable play for a third baseman who hadn’t played more than a handful of games at the position in five years, one for whom going to his backhand was the area of greatest vulnerability this spring.

"Backhanded took me a little bit," said Shaw, who has been credited with three Defensive Runs Saved at third base already this season. "That’s the one I worked on the most in spring training. That was something that was a focal point for me."

"He said that that was a problem," infield instructor Brian Butterfield said with a grin, "but it hasn’t been a problem as far as my eyes have seen."

As well as he has hit the ball this season, where Shaw truly has been a revelation -- and where he really wrested the starting job from Pablo Sandoval -- is at third base.

The labrum surgery Sandoval underwent Tuesday will sideline him for the season, making Shaw the clear-cut starter at third base at least for the rest of the season. Perhaps Sandoval would have undergone season-ending surgery no matter what, but the way Shaw has handled himself defensively at third base had to make it a little bit easier for Boston to put their primary backup plan on the shelf for the year. Defying expectations, Shaw has emerged as a viable big-league third baseman.

"I don’t consider myself a one-side-of-the-ball player," he said. "I care about defense. I probably care more about defense than I do offense."

What has been most remarkable about Shaw is the way he’s handled every type of defensive play he could be asked to make.

"He’s an awful good athlete," Butterfield said. "He’s got a big body, and some people are misled by that body. He’s got good body control. He’s very athletic. He’s got a lot of confidence. There’s never any panic to his hands when his feet don’t take him to the hop."

Shaw has made routine plays look routine. He has gone to his left effectively. He has shown the mobility to come in on in-between choppers toward the shortstop, something he did twice Tuesday night even with runners crossing in front of him both times. He has made a habit out of picking the ball off the ground with his bare hand and throwing to first base almost in a single motion, as he did on a sacrifice bunt on Sunday.

Fielding the ball barehanded -- something he did to sensational effect the first week of the season in Toronto -- is something that he picked back up as quickly as he could have expected. He’d been doing it all along, even if it wasn’t for any particular purpose.

"It’s something that you just mess around with," he said. "It’s not something you practice, but for me, in the infield, I’d always fool around with it. Even when I played first, I’d still mess around with it. That has stayed with me."

Going to his backhand, however, was less natural. He never had to do it much as a first baseman. As a general rule, if a play took him more than a step and a half to his right, his instinct was to leave it for his second baseman to field -- especially if that second baseman was Dustin Pedroia -- and to go cover first base. Ranging too far to his backhand side from first base meant forcing his pitcher to cover first base.

"It was something I never really worked on much because you don’t need to do it," he said.

And so, when Shaw got to spring training, he went to work with Butterfield on shoring up that aspect of his defensive game. He took repeated ground balls to his backhand side. He made mistakes -- he failed to handle such a ground ball in an exhibition game in late March -- but he’s been nearly flawless since the regular season began. He made a sensational diving stop to his backhand side and then a strong throw to first against Tampa Bay in late April. The play that saved a run Sunday was just the latest example.

"One thing that he does is that if he feels like there’s a part of his game that’s a little bit of a negative, he really works hard to try to clean it up," Butterfield said. "This goes back to last year, too. Every little thing that he does, there’s a purpose with his defensive work, and because of his work, he’s gotten a lot better."