On his 500th club appearance, his 416th for United following his 84 games for Atletico Madrid, the Spaniard had to come off due to injury, and must be a doubt for Wednesday's crunch Champions League tie with Paris Saint-Germain.
The keeper crashed into a post as he tried, in vain, to save James Ward-Prowse's free-kick which sent the Saints 2-0 up at St. Mary's. De Gea finished the first half for the Reds but came off at the interval, with Dean Henderson making his league debut for United.
United manager Ole Gunnar Solskjaer was asked about the condition of our no.