Chelsea boss Thomas Tuchel said there were a number of reasons Christian Pulisic was deployed as a wing-back against Arsenal.
Pulisic played on the right and Callum Hudson-Odoi the left at the Emirates Stadium, where the Blues won 2-1 in pre-season friendly.
Marcos Alonso was unavailable and therefore not an option on the left, while Tuchel was also keen to have a look at Hudson-Odoi in that position.
And with Reece James and Cesar Azpilicueta, who are usually the main options on the right, being eased back in after being away at Euro 2020, Tuchel decided to play Pulisic there.
The German explained: “Marcos was not able to play today so we put Callum on the left side - it was something I wanted to see for a long time. Callum can maybe be more dangerous from this position.
“We have Azpi and Reecey for this position (on the right). Both of them are not here. Azpi started two days ago and Reecey did not even start yet.
“So we lack solutions. And was a possibility to give him (Pulisic) some minutes.”
Pulisic, who previously worked under Tuchel at Borussia Dortmund, played just over an hour of Sunday’s game.
Asked if the American could be used as a wing-back again in the future, Tuchel said: “Maybe. He played this with me in Dortmund.”