BOSTON -- Aaron Hicks¡¯ season could be in jeopardy after the outfielder experienced a setback in his recovery from a flexor strain in his right elbow, Yankees manager Aaron Boone said prior to Saturday¡¯s game against the Red Sox.

Boone said that Hicks has been unable to resume throwing following the injury, which he sustained in an Aug. 3 game against Boston. Hicks was sent for a dye-contrast MRI this week that revealed no new concerns with his ulnar collateral ligament.

¡°Everything checked out really well, so that¡¯s encouraging,¡± Boone said. ¡°He¡¯s still not quite where he needs to be to start ramping up.¡±

Hicks, 29, signed a seven-year, $70 million contract extension in February and did not make his season debut until May 15 because of a lower back injury. In 59 games, Hicks batted .235/.325/.443 with 12 homers and 36 RBIs. Boone said that Hicks must resume throwing before he can swing a bat.

¡°He was looking forward to throwing and starting to throw,¡± Boone said. ¡°He might get a second opinion to make sure. We feel good about where he is from an injury front, but it¡¯s not getting to that point to where we¡¯re able to advance him into baseball activities.¡±

If Hicks is unable to return, Brett Gardner would likely continue to start regularly in center field. Mike Tauchman and Cameron Maybin have been largely splitting time in left field, though Maybin has been slowed of late by lingering soreness in his left wrist.

¡°The wrist is something he¡¯s going to have to deal with the rest of the season,¡± Boone said of Maybin. ¡°It¡¯s not perfect, but he is an active player. I would go to him in a situation. It¡¯s something he might have to deal with [surgically] after the season.¡±

Yanks must make a decision about Sevy

The Yankees saw mostly positive signs from Luis Severino¡¯s 50-pitch effort for Double-A Trenton on Friday evening, in which the right-hander allowed a run and five hits over three-plus innings, but Boone said there is a chance that Severino could remain in the Minors to make another rehab start.

¡°I thought he looked certainly a lot better than his first time out, which was like his first Spring Training start,¡± Boone said. ¡°I thought he was a lot sharper. Good life on the fastball. I thought the shape was better on the slider. He threw a lot of changeups and had pretty good results, too. It was a big step forward for him.¡±

Severino told reporters in Trenton, N.J., that he feels ready to be activated and face big league competition. Boone said that the Yankees expect to decide Severino¡¯s immediate future by the end of Saturday¡¯s business.

¡°What¡¯s the best environment to continue to build him up?¡± Boone said. ¡°Is it better to have him go one more [in the Minors] and build up his pitch count in a more controlled environment like that, or just get him here and rolling? To me, he¡¯s demonstrated enough to be an option.¡±

Boone watched Severino¡¯s entire outing on video, and is also keeping tabs on Dellin Betances, who threw a scoreless inning on Friday for Trenton. Boone said that Betances showed signs of rust in his first outing of the season, but overall he looked good. Betances is expected to pitch again on Monday.

¡°I thought he threw some good breaking balls and threw some good fastballs in there,¡± Boone said. ¡°He was a little erratic. Talking to him, I think he felt good about it. Now you¡¯re dealing with a little bit of rust [like in the] early outings of Spring Training.¡±

On the comeback trail

Giancarlo Stanton (right PCL strain) was scheduled to have more simulated at-bats at the Yankees¡¯ complex in Tampa, Fla., on Saturday. Boone said that Stanton has been performing agility drills and running the bases, in addition to taking part in outfield drills.

Gio Urshela (left groin tightness) is expected to be activated from the injured list prior to Sunday¡¯s game. Urshela last played on Aug. 28 at Seattle.

Going for the gold

The Yankees joined all of Major League Baseball on Saturday in helping to raise awareness for childhood cancer by having all on-field personnel, including players and coaches, wear gold ribbon decals and wristbands during their game against the Red Sox.

This is the fourth consecutive year MLB has held ¡°Childhood Cancer Awareness Day,¡± in recognition of September as Childhood Cancer Awareness Month in collaboration with Stand Up To Cancer. Childhood cancer is the leading cause of death by disease among children in the U.S. and Canada.

This date in Yankees history

Sept. 7, 2014: The Yankees held ¡°Derek Jeter Day¡± in front of a sellout crowd of 48,110 at Yankee Stadium. Jeter went 1-for-3 with a walk in New York¡¯s 2-0 loss to the Royals.