It raises more question marks over the Spain star's long-term future, although new Southampton boss Mauricio Pochettino had some sympathy for De Gea.
"It is clear to me that any free-kick near to the box, or a corner, presents a goalscoring opportunity," he said.
"That doesn't happen as much in the Spanish league.
"Also, the goalkeeper in Spain is a bit more protected than here. That makes their job here a lot harder."