A sore back might have contributed to Bryce Harper’s struggles in the second half of the season. J.T. Realmuto said Tuesday night that Harper has been dealing with back soreness for longer than most were aware.

Harper’s back did not cause him to miss any time this season until he removed himself from Sunday’s loss to Toronto. But Realmuto said Harper’s back did not just flare up for the first time a few days ago.

“His back has been nagging for quite some time, and people didn’t even know it really until recently,” Realmuto said after Tuesday night’s 8-7 loss in Washington. “He’s been playing through some stuff for a while, but he’s the kind of guy who if there’s any opportunity for him to be in the lineup, he’s going to be out there and try to help the team.”

Harper left Sunday’s loss with soreness in his lower back and returned to the lineup Monday. He played both games of Tuesday’s doubleheader, but did not look to be 100%. Realmuto, who missed 11 games with a sore hip, returned Tuesday and played both games of the doubleheader as the Phillies added reinforcements for the final days of the playoff race.

“I’ll ask him how he’s feeling and he’ll ask me how I’m feeling, but it’s kind of understood between both of us that if there’s a chance, we’re both going to play and we’re both going to go out there and give the team everything we have,” Realmuto said.

The sore back could explain why Harper struggled offensively after a torrid start to the season. He was hitting .343 with a 1.192 OPS and seven homers through his first 22 games. Since then, Harper is hitting .185 with a .697 OPS and four homers in 32 games. A sore back might have derailed his MVP pace.

“I don’t exactly know the timeline of it,” Realmuto said. “But I know he’s been hurting for longer than most people know.”