NEW YORK -- Yankees first baseman Greg Bird stood in shallow right field and played catch with Carlos Mendoza, the team's infield coordinator.

Sounds boring to you. To the Yankees, it's like hearing The Beatles.

That's because it was a sign Bird could be back sooner than the team initially expected, manager Aaron Boone told reporters before Monday's game against the Marlins at Yankee Stadium.

Bird started the season on the disabled list following surgery to remove a right ankle bone spur. He was expected to miss between six and eight weeks, but Boone said the 25-year-old's recovery has gone so well that the club has higher hopes.

"He's doing really well," Boone said when asked when he thought Bird could start playing in rehabilitation games.

"It's going well. We're optimistic that it's maybe going to be on the shorter side of things. But when that is, I'm not exactly sure, but I know he's moving in the right direction and he's passed every test so far and the facet he's doing all these things is a really encouraging sign. I'm excited about his progress and where he is and hopefully being on the shorter side."

Tyler Austin has hit two home runs with six RBI and a .265 batting average in 39 plate appearances. Neil Walker has hit .188 with no homers and three RBI in 53 plate appearances.

Combined, Yankees first basemen have posted a .634 OPS. That's 20th-best in the league.

Brendan Kuty may be reached at bkuty@njadvancemedia.com. Follow him on Twitter @BrendanKutyNJ. Find NJ.com Yankees on Facebook.