#1 David De Gea
Who else could have been on top of this list? David De Gea is definitely one of the best in the world and it wouldn't be wrong to say that he is the best in the world. He had a dream run in the last season.
In the 37 games he played last season, he kept 18 clean sheets and conceded only 28 times. He won the Premier League Golden Glove as well.
He was one of the best players for Manchester United last season and delivered some world-class performances. If he had a better defense to support him, The Red Devils could have had a much better season and perhaps pushed City for the title.
With Mourinho looking to rope in strong defenders, one shouldn't be shocked if he concedes less than 22 or 23 goals.