NEW YORK -- The Yankees feared the worst when Aaron Hicks mentioned pain in his throwing elbow on Saturday evening, which is why they were encouraged when the outfielder's MRI examination on Sunday revealed only a right flexor strain.

Hicks was placed on the 10-day injured list, with left-hander J.A. Happ coming off the paternity list to start against the Red Sox. Though there is no timetable for Hicks' return, manager Aaron Boone said that the Yankees are optimistic that Hicks will play again this season.

"The fact that the ligament is intact is good news," Boone said. "He'll be shut down for the next seven to 10 days from throwing, and then at that point, hopefully he's in a position to start ramping back up again."

Hicks injured his right elbow on a sixth-inning throw to third base Saturday, catching Christian Vazquez's fly ball and throwing on a line to third baseman Gio Urshela, holding runner Sam Travis at second base.

When Hicks reported it later to head athletic trainer Steve Donohue, Hicks was replaced for a pinch-hitter in the eighth inning. Though Hicks said that he was hoping for the best, the phrase "Tommy John surgery" crossed his mind.

"I think we were all kind of worried that it could be that," Boone said. "That's ruled out. Now it's just making sure it's healed and recovered."

With Hicks shelved, Boone said that the Yankees should be covered with Brett Gardner, Aaron Judge, Cameron Maybin and Mike Tauchman in the outfield. Gardner will take over as the regular center fielder, with Maybin and Tauchman potentially seeing time at all three positions.

Boone added that the Yankees did not consider promoting Clint Frazier from Triple-A Scranton/Wilkes-Barre to replace Hicks.

"We're at three position players now [on the bench], so we'll probably stay this way," Boone said. "I'm sure there's a chance we have some fluctuation in who those guys may be, but right now we feel like we're covered how we should be."

If at first ...

With Edwin Encarnacion (right wrist fracture) and Luke Voit (sports hernia) both out with injuries, the Yankees plan to use DJ LeMahieu and Mike Ford as their first-base combination, with Gio Urshela also available for occasional duty there.

"Ford probably will DH some here in the foreseeable future as well," Boone said. "We’ll just kind of mix and match depending on matchups and maybe who’s down that day, so for Ford, it’s obviously first base/DH, and obviously with DJ, we have the flexibility of plugging him anywhere. Ford will get some at-bats, though."

Yes in-Didi

Didi Gregorius returned to the Yankees' lineup on Sunday, having missed three games with a strained ligament between his left ring and pinkie fingers. Gregorius took batting practice and grounders between the games of Saturday's doubleheader sweep of the Red Sox.

"That all went well," Boone said. "When I talked with him [Saturday] night, he felt pretty good where he was at. Obviously, I'll be mindful of it and we'll watch him closely. I feel like he's in a good spot."

Comeback trail

Gary Sanchez (left groin strain) is expected to begin a Minor League rehab assignment this week, with hopes of rejoining the active roster for the series that begins on Thursday against the Blue Jays in Toronto. Sanchez ran the bases on Sunday at Yankee Stadium.

This date in Yankees history

Aug. 4, 2010: Alex Rodriguez became the seventh (and youngest) member of the 600-homer club, slugging the milestone blast off the Blue Jays' Shaun Marcum in a 5-1 Yankees victory. The homer came three years to the day of Rodriguez's 500th homer, on Aug. 4, 2007, off the Royals' Kyle Davies.