There was a “Sign J.T.” banner outside Citizens Bank Park before the season opener. Some fans outside the ballpark chanted it each time J.T. Realmuto batted this season. And a popular pizza shop wrote it inside Bryce Harper’s pizza box, as the area seemed to be overtaken this summer by the campaign to bring back Realmuto.

But Realmuto is not the only player who Matt Klentak — or whoever the team’s general manager will be this offseason — needs to try to retain.

Didi Gregorius, who has a career-high batting average and OPS this season, while leading the Phillies in hits and RBIs, will be a free agent after outperforming a one-year $14 million deal. There may not be a “Sign Didi” movement, but the shortstop proved that he could have a longer stay than just one season.

“I love them both,” manager Joe Girardi said of Gregorius and Realmuto before Saturday night’s game. “Those are decisions for the offseason. No one really knows what the financial state of our game is going to be.”

The free-agent market has slowed in recent seasons, as teams have seemed less eager to sign long-term contracts. Combine that with a season of empty seats and a collective bargaining agreement that expires after next season, and it could be another slow winter.

It might not be the best offseason to be a free agent, but Gregorius should headline a shortstop market that includes Oakland’s Marcus Semien, the Angels’ Andrelton Simmons, and Toronto’s Jonathan Villar.

Gregorius, who will turn 31 in February, entered Saturday hitting .290 with 40 RBIs and a .849 OPS. There should be a market for his services. Without Gregorius, the Phillies could return Jean Segura to shortstop and play Scott Kingery at second base and Alec Bohm at third.

But the lineup would miss Gregorius' bat. The defense would miss Gregorius' glove, as he was graded by some advanced metrics to be one of baseball’s best shortstops. And the clubhouse would miss his presence, which was a big reason Girardi implored Klentak to sign Gregorius last winter.

“I just think it’s the attitude that he brings,” Girardi said. “I think you see more and more of it as time goes on. When you come into a clubhouse for the first time, it’s not always so easy to be yourself and ask other players to do certain things. But I think he’s gotten more and more comfortable as time went by.”

Extra bases

Aaron Nola will start Sunday’s season finale at Tampa Bay. … Jake Arrieta threw off a mound Friday in Tampa, and Rhys Hoskins could take batting practice. Both are candidates to return from the injured list if the Phillies reach the postseason. … Zach Eflin could be available out of the bullpen on Sunday.