Atlanta United was beginning to lose control of in the opening minutes of the second half in Saturday’s MLS playoff game against New England at Mercedes-Benz Stadium.

New England’s outside backs were pinning Atlanta United’s wingbacks deep in their own half. Atlanta United was having trouble winning the ball and, when they did, getting it to Ezequiel Barco in the half-spaces between the Revs’ lines.

Manager Frank de Boer, who has said time and time again that he isn’t afraid to make choices, chose to change the formation from a 3-4-2-1 to a 4-3-3. In came the speedy Hector Villalba as the left midfielder and the imposing Flo Pogba as the left fullback. Julian Gressel moved from right wingback to right midfielder.


Suddenly, New England's midfielder and back line had new threats with two players attacking them. They were pushed back. The field opened. Atlanta United soon scored on a goal by Franco Escobar, who moved from centerback to right fullback when the formation changed, and advanced 1-0.

» NEXT MATCH: Atlanta United faces Philadelphia in semifinals

“I wanted to bring some fresh blood in, and I think in that period we didn’t have the control anymore,” de Boer said. “So, that’s why I changed to four in the back. If you want to bring in Tito (Villalba) then you have to have somebody behind him. So that’s why I swapped to the 4-3-3 formation. I think that it resulted in us getting the control back. We created chances as well.”

It was the second time in as many games against New England that de Boer switched from three in the back to four and it resulted in a victory. The first was a 3-1 win on Oct. 6 when Josef Martinez scored the winner after a fantastic pass by Gressel.

“I think they struggled to come up with anything different after that and it made it easier for us to attack them,” said Emerson Hyndman, who was subbed out in place of Pogba.

On the winning goal, Escobar, Gressel and Barco combined with Escobar splitting two defenders who were focused on Gressel. Barco put the pass into space for Escobar to run onto and one-time a shot.

Atlanta United will host the Eastern Conference semifinal on Thursday. De Boer's choice of formation is going to be interesting because he has just three healthy true centerbacks and no true left fullback. Centerback Miles Robinson is likely out with a strained hamstring. Michael Parkhurst, who started in place of Robinson, left the game in the closing minutes because of a dislocated left shoulder. The situation is so odd that de Boer jokingly asked a journalist if he could play centerback. (No, was the answer).

If de Boer chooses to start the semifinal with a 3-4-2-1 formation, he will use all of his centerbacks and won’t have any on the bench in case there is another injury or other issue. De Boer could use Jeff Larentowicz, but he is playing well as a starting defensive midfielder the past two games.

But it’s the absence of a true left fullback — an injury-caused problem for three seasons now as the team goes through left backs with the frequency of the fictional band Spinal Tap and its drummers — that may dictate the formation. The team can use either Justin Meram or Villalba as left wingbacks in a 3-5-2 formation. Their defense is good enough in that formation. Neither can play as a true left fullback in a 4-3-3. Pogba has played left fullback four times this season, so he can do the job. He executed well in Saturday’s win. But he is better suited to play centerback. Mikey Ambrose has played well for Atlanta United 2 as a left fullback. He hasn’t played for the senior team in a league game since June 7.

De Boer said he typically decides the formation 3-4 days ahead of the game. He typically consults the players on what they feel comfortable with because he said they are the ones that must execute. Then, the team trains the formation.

“Whether it is four, three, or five in the back, ultimately, it does not matter,” goalkeeper Brad Guzan said. “When you have guys on the field, you have got to be willing to run and fight and do that, because we have talented players that can raise the game. We can play good football, but if you are not going to do the dirty work then you are not going to give yourself the chance to win games.”