Paul Merson believes former club Arsenal could start playing with a three-man defence as a result of the recent arrivals of Kieran Tierney and David Luiz.
After seeing his team concede 51 league goals last season, Gunners boss Unai Emery bolstered his defensive options for the new campaign by adding both players to his squad on deadline day.
However, Merson is expecting both defenders to play a key role in Emery's plans going forward and believes their inclusion could prompt the Spaniard to move away from the back four he used at St James' Park on Sunday.
"When you're looking at them and you're naming them players, I wouldn't be surprised if he started going to a three at the back," Merson said on Sky Sports.
"Play them two and David Luiz in the middle of them.
"He can come out and play, you've got Tierney playing as one wing-back.
"I think it suits all of the defenders.
"If you have three centre-halves playing there it gives all of them something to fall back on.
“If Tierney can get forward he can play, so he'll want to get forward."