His absence likely will mean that Emerson Hyndman will start as the attacking midfielder. Hyndman, 23, has eight appearances, including three starts, in the league.

De Boer also said that defender Franco Escobar likely won’t start against the Union because he is still working his way back from a hamstring injury and that the team wants to be careful because he is a key player and they don’t want to lose him for the season.

Escobar played the final minutes of the U.S. Open Cup. He said Thursday that he’s not 100 percent, but is close. Escobar, 24, has 19 appearances this season. With Escobar likely not starting, the back three for Atlanta United likely will continue to be Miles Robinson, Leandro Gonzalez Pirez and Flo Pogba.