Jose Mourinho felt his decision to start both Marcus Rashford and Anthony Martial left Manchester United open defensively against Newcastle United, even if it ultimately paid off in Saturday's big victory.

The Red Devils ran out comfortable 4-1 winners at Old Trafford despite an early scare when Dwight Gayle scored, with Martial nodding the equaliser before Chris Smalling, Paul Pogba and Romelu Lukaku secured victory.

Mourinho selected an exciting, attacking line-up, playing a front three of Rashford, Martial and Lukaku, with the fit-again Zlatan Ibrahimovic on the bench, but he acknowledged that it was this system that allowed Newcastle to enjoy a bright start.

"[Rashford and Martial] both like to play in the same position and that is difficult," Mourinho said.

"They both prefer to play on the left than the right, both playing with another striker through the middle; we lose a point of contact with the midfield that we are used to, with the player playing behind the striker.

"But we found then a certain balance and, when they started finding one opening on the left and one on the mid-left between the striker and the left winger, that was the moment where we start creating more.

"But, to be honest, Newcastle were probably the [better] team - not in the second-half, but in the first-half - and we felt a bit of instability in our defensive areas.

"That was clearly not because of the defensive players but because of our balance. To play them together gives us things but also takes some things from us."