CLEARWATER, Fla. -- Aaron Hicks' lingering back injury required a second cortisone injection on Sunday morning, which will keep the Yankees' outfielder from taking the field with his teammates on Opening Day.

Yankees manager Aaron Boone said Hicks will begin the season on the injured list, though by back-dating his injury, it is possible that Hicks could return for the second week of games.

"We just want to make sure this isn't something that lingers during the season," Boone said. "But with that, that will definitely take him out of being ready by Opening Day. I think he physically probably will be ready, but we'll need to build him up and get him some games under his belt before he gets down there. Hopefully this will knock it out once and for all, but it will slow him down by a couple of days."

The switch-hitting Hicks experienced stiffness in his lower back while taking batting practice before a March 1 game against the Orioles in Tampa, Fla. The 29-year-old agreed to a seven-year, $70 million contract extension in February.

Boone indicated that Hicks' injury makes it more likely that the team will be able to carry both Greg Bird and Luke Voit, who have been competing to serve as the Opening Day first baseman.

"I think we're looking at two impact players," Boone said. "There's probably more of a case now that both could be part of things. But I know that I'm looking at two really good players."

Brett Gardner is expected to man center field for the opener, with Giancarlo Stanton patrolling left field. Bird or Voit could serve as the designated hitter.

"I still don't believe Hicks is going to miss that much time," Boone said. "I feel like we can handle it internally right now."

With the Yankees strongly considering carrying 13 pitchers to open the season, catcher Austin Romine and infielder DJ LeMahieu would join the extra first baseman on the bench. Outfielder Clint Frazier and utility man Tyler Wade project to battle for the remaining position-player spot.

Frazier missed most of last season while recovering from the effects of a concussion, and the Yankees have said they want him to gain regular at-bats -- an opportunity that may not exist at the big league level.

The versatile Wade started in center field on Sunday against the Phillies, and Boone said that was a direct result of Hicks' situation, as well as the fractured right wrist that will sideline top prospect Estevan Florial for a yet-to-be-determined period.

"This becomes an important week for us, just trying to evaluate and make the best decisions," Boone said. "We don't think it's going to be a long time for Hicks, but that'll factor into it. How many pitchers we go with, how we can figure that, those will all be conversations that we have that will be ongoing throughout the week. But I would say, we haven't decided anything yet."