New York City FC center back Maxime Chanot knows what his team shouldn't do in their preparations for Sunday's Eastern Conference Final at the Philadelphia Union (3 pm ET | ABC, ESPN Deportes).

"The biggest mistake we could make would be to change the way we prepare," Chanot said in Friday's media availability. "We haven’t changed anything."

But NYCFC will have a massive change imposed upon them when chasing their first-ever MLS Cup place, with Golden Boot presented by Audi winner Valentin Castellanos serving a red card suspension.

And manager Ronny Deila certainly appears open to multiple approaches to replace Castellanos' 21 combined regular season and playoff goals.

"We have at least two, maybe three players who can play that position," Deila said as their Audi 2021 MLS Cup Playoffs journey continues. "We can also play a false nine. So we have options."

Castellanos has scored in both of NYCFC's postseason contests, including a 109th-minute goal in Tuesday's Conference Semifinal against the New England Revolution. He received his second yellow card four minutes later in what finished a 2-2 draw, with the Cityzens advancing via penalty kicks.

Castellanos also found the net in two of three regular-season games against Philadelphia. (The teams each took four points from nine in that season series.)

Two years ago, his most obvious replacement would've been Brazilian striker Heber, who scored 15 goals across 22 appearances in 2019.

But after returning from a long ACL rehab, he's made only seven appearances and played 95 minutes in 2021. That's partly because of Castellanos' blazing form, and partly because Heber offers a different profile.

"A player like Heber has done it in this league and has shown me many times, and I almost feel a little bit sad that I haven’t used him more because Taty has been unbelievable," Deila said.

Talles Mango and Ismael Tajouri-Shradi are other likely options should NYCFC go with a true center forward. And reading between the lines, it may be a by-committee approach, since none of that trio is accustomed to playing 90 minutes.

"It will be important to have both Talles and Heber," Deila said. "And we’re going to use both of them in the game I’m sure."

Said Chanot: "Obviously everybody’s sad to play without Taty, but I’m pretty sure the player who is going to fill the gap will be as good as Taty."

There's better news elsewhere on the pitch for NYCFC, with Deila saying everyone who was available in New England would be again Sunday.

That includes defender/midfielder James Sands, who left injured in the 82nd minute, and right back Tayvon Gray, who was hobbled by cramps deep in extra time.

And Deila agreed with Chanot's sentiment about keeping preparations on the same conceptual plane they've always been.

"It’s like going to an exam," Deila said. "When you haven’t learned until the last day, you can’t do anything. You have to trust the process throughout the year.

"It’s not about inventing something or finding new things. It’s about believing in what you have done and do the same things as you always have done."