Atlanta United (4-1-0) will host NYCFC (5-0-1) at 6 p.m. Sunday at Mercedes-Benz Stadium.

What was expected to be a high-scoring affair may not materialize because of injuries.

For Atlanta United, striker Josef Martinez suffered an apparent injury on Wednesday. Forward/midfielder Hector Villalba also didn't train. David Villa came off the bench to play in NYCFC's win against Real Salt Lake on Wednesday.

Michael Lewis (@soccerwriter) answered three questions about NYCFC ahead of the game:

Q. How would you explain the team's success without David Villa?

A. The team has greater depth this season with more experienced players in the second-line roles. Ismael Tajouri-Shradi has been nothing but superb coming on cold and connecting four times in three games because of Villa's calf injury. Because the team follows its system extremely, it will give the forwards an opportunity to create chances regardless who is in the strikers' role. When Villa first missed some action against New England, the team endured a horrible first half against New England before bouncing back in the second half for a 2-2 draw behind Tajori-Shradi's brace.

Q. What is the key match-up for Sunday's game?

A. It would be easy to say Villa against any of the two center backs if he is healthy. But I think it will be in the midfield. That has been vital to City's success this season. Can Maxi Moralez, Yangel Herrera and Ebenezer Ofori impose their will on Mikey Ambrose, Jeff Larentowicz, Darlington Nagbe, Miguel Almirón, Julian Gressel? Or vice versa.

Alex Ring, who has established himself as one of the premier defensive midfielders in the league, suffered an injury during the recent international break. He started Wednesday night's game against Real Salt Lake on the bench. I realize Atlanta outnumbers NYCFC in the midfield, but the visiting trio will have help on the wings thanks to the outside backs, whether it be Anton Tinnerholm, Saad Abdul-Salaam or Ben Sweat.

Q. Sean Johnson, an Atlanta native, is having a phenomenal season. What's been the key to his success?

A. Johnson has saved NYCFC's backsides in three games this season. He is playing confidently. His decision-making process has been immaculate as Johnson has positioned himself well to make saves. And when shots "come out of nowhere," he has the reflexes to make a spectacular save or two. It hasn't hurt that the defense has limited the quality of shots, allowing Johnson a better sight line on them.