Neither Ezequiel Barco nor Franco Escobar trained with Atlanta United on Tuesday.

Barco, an 18-year-old midfielder and the most expensive transfer in MLS history, hasn’t trained with the team since sustaining a quadriceps injury the week of the season opener.

Manager Gerardo Martino said two weeks ago that there was a chance Barco could return this week.

The Five Stripes will play at Minnesota United on Saturday.

Escobar, a defender, sustained a concussion after colliding with goalkeeper Brad Guzan during the 4-1 win against Vancouver more than a week ago at Mercedes-Benz Stadium. Escobar, acquired in the offseason from Newell’s Old Boys in Argentina, started the season’s first three games.

If Escobar doesn’t return in time for Saturday’s game, Martino could either use Julian Gressel, Jeff Larentowicz, Chris McCann, Sal Zizzo or Miles Robinson as the third centerback if the team uses a 3-5-2 formation. Should they use a 4-3-3 formation, Martino would likely choose between Zizzo and Gressel. Zizzo started three games at right fullback during the preseason.

Brandon Vazquez, who has missed the past three weeks, trained with the team on Tuesday.