PHILADELPHIA – J.T. Realmuto’s right shoulder has been a concern for the Phillies for weeks because they need the best catcher in baseball in the lineup, even if it means he plays first base, like he played Wednesday night at Citizens Bank Park.

They need him hitting behind Bryce Harper, too.

Realmuto helped the Phillies keep their postseason hopes alive in Wednesday’s 6-5 walk-off victory over the Cubs. After Chicago intentionally walked Harper to face Realmuto in the fifth, he hit a two-out single to score a run. He then hit a go-ahead home run to right in the eighth, after Philadelphia's bullpen blew its 31st save of the season in the top of the inning. The Phils wasted Realmuto’s blast when they blew their 32nd save of the season in the ninth, only to win when Andrew Knapp scored from third base on a passed ball.

It was the first time the Phillies won on a walk-off passed ball since Jimmy Rollins against the Cubs on Aug. 3, 2005. It was the seventh time they have done that since 1901, according to Baseball Reference.

Because the Braves (76-68) lost on Wednesday, the Phils (73-72) moved within three games of first place in the National League East with 17 games to play. Philadelphia is also three games behind St. Louis (76-69) for the second NL Wild Card spot, although San Diego (74-70) and Cincinnati (75-71) are ahead of the Phils in the standings, too.

“We know where we’re at,” Knapp said. “We know what this team can do. I know that we can do it. I know that tonight’s win is how we’re going to have to do it. You’re not going to always just have a lead and keep a lead throughout a game. Sometimes you’re going to get punched in the face, but we’ve been talking about just being able to flush everything and really focus on the next inning, the next pitch, and going out and continuing to battle. I think it would have been really to just crumble after giving up the lead a couple times.”

But it is difficult to imagine the Phillies winning the division or the second Wild Card spot without Realmuto.

The Phillies’ offense is struggling. They miss first baseman Rhys Hoskins, who had season-ending surgery on Aug. 31. They expected Alec Bohm to be a major player at third base, but he is nursing an injury in Triple-A. They have not gotten the production they expected from shortstop Didi Gregorius. Andrew McCutchen has struggled against lefties.

Realmuto has struggled, too. His right shoulder is a factor, although how much only Realmuto knows. But he received a cortisone injection on Sunday, which kept him out of the lineup on Tuesday.

Phillies manager Joe Girardi started him at first base on Wednesday to give him another day without throwing. He hopes to have Realmuto back behind the plate on Thursday.

“He’s a stud,” Knapp said. “He’s putting his body on the line each and every day. We ask him how he’s feeling, and he keeps it pretty close to his chest. But for him to have to go and get a shot, it’s obviously been bugging him. But I see it as an opportunity for us to be able to fill in when we can and to step up when we need to. For him to be able to come off of that and get a couple hits, especially that huge home run, he’s just a grinder. He’s out there, he’s a leader and we need him on the field. That was huge for us.”

Realmuto’s three hits on Wednesday raised his season splits to .267/.352/.445 with 15 home runs, 62 RBIs and a .797 OPS.

And he has six hits in his last two games. Maybe it makes teams rethink pitching around or intentionally walking Harper. Surprisingly, it was just the 10th time this season Harper has been intentionally walked. Now, that's surprising because Harper is putting up numbers that should earn him consideration for the National League MVP Award. He entered Wednesday slashing .341/.474/.736 in 234 plate appearances since the All-Star break.

Harper's 1.210 OPS would be the third highest in franchise history following the All-Star break, trailing Ryan Howard (1.259 OPS) in 2006 and Mike Schmidt (1.214) in 1981.

Howard got intentionally walked a franchise-record 37 times in 2006.

Schmidt got intentionally walked 18 times in the strike-shortened 1981 season.

“Bryce is having an MVP season,” Freddy Galvis said. “The guy behind him is going to do the job. That’s the way it’s going to be.”