Former Premier League official Dermot Gallagher has suggested that he could understand why the assistant failed to rule that Arsenal's second goal against Everton was offside.

Pierre-Emerick Aubameyang doubled Arsenal's advantage shortly after Alexandre Lacazette's opener, but the Gabon international was a yard offside when converting from close range.

Gallagher said that the assistant had a "momentary blip of concentration", but indicated that he saw why the decision had not been given.

"If you look at the assistant just before that, he was slightly out of position so he's looking across and hasn't got the right angle," Gallagher told Sky Sports News.

"It's a momentary blip of concentration. Those incidents, I say it week in and week out, you've got to take a photo in your mind of where was he when the ball was last played so when that ball is played by Ramsey, you think 'oh that's where he was'."

Arsenal went on to register a 2-0 triumph over the Toffees at the Emirates Stadium.