Sebastian Stan and Anthony Mackie haven't even started production on Marvel's The Falcon and the Winter Soldier yet, but they were present at the D23 Expo 2019 on Friday, Aug. 23 to tease what's ahead for their fan-favorite Marvel characters.

The last we saw of the duo in Avengers: Endgame, they were helping Captain America (Chris Evans) return the Infinity Stones back to their original locations in the timeline and, in the case of Sam, receiving Cap's shield. Now they'll be a crime-fighting duo in the new Marvel series heading to Disney+ in the fall of 2020. How will the two best friends of Steve Rogers function without him, though?

"He was our third wheel. He was our third leg in the race," Mackie told TV Guide on the Disney+ press line after the presentation. "You need that third leg to complete the race," Stan added.

That doesn't sound too optimistic, but the actors said that Sam and Bucky are doing a lot better together than they were when we saw them bickering in Captain America: Civil War.

"We're learning from reach other. We're thriving. We've been through relationship counseling," Mackie joked.

Everything We Know About The Falcon and the Winter Soldier on Disney Plus

"It's a developing relationship," Stan added. "You just keep on, carry on."

While it's obvious there's not much the two can say about the actual plot of The Falcon and the Winter Soldier — we know that Daniel Bruhl's Zemo and Emily VanCamp's Sharon Carter will appear in the limited series — TV Guide did get one important update about the status of Bucky's hair. He was still sporting shoulder-length hair at the end of Endgame, but he might have a shorter 'do in The Falcon and the Winter Soldier.

"We had to cut it," Mackie joked. "No respectable man wears that hair."

Guess we'll find out for sure when The Falcon and the Winter Soldier premieres on Disney+ in fall 2020.

Additional reporting by Lindsay MacDonald

Anthony Mackie and Sebastian Stan, D23 ExpoAnthony Mackie and Sebastian Stan, D23 Expo