De Gea refuses to deny 'release clause' in deal
There has been speculation there's a £30m buy-out clause in the four-year deal he signed last month that would allow Real Madrid to reignite their interest in the Spaniard next summer.
And asked about the release clause following Spain's 1-0 win over Ukraine on Monday night, De Gea was giving nothing away - and instead redirected the question to his agent Jorge Mendes.
De Gea said: "You should ask Jorge that question.
"He is the one who pays attention to those sort of details."
De Gea looked set for a move to the Bernabeu on deadline day only for the deal to collapse at the last minute.
Both clubs blamed each other in the aftermath before the 24-year-old signed an extension to his contract - that was due to expire next summer - that could keep him at Old Trafford until 2019.
Meanwhile, United defender Paddy McNair is to remain in Helsinki for another night for further assessment on the abdominal injury sustained on Northern Ireland duty.
It is understood the 20-year-old is still being monitored at a hospital in the Finnish capital.
McNair was injured in the 13th minute of Sunday's 1-1 draw against Finland - a result which saw Michael O'Neill's men win Euro 2016 qualifying Group F - but played on until the 51st.
He was unable to travel home with the rest of the squad. It is understood McNair suffered bad bruising to the ribs and the area immediately below.
McNair has played just once for United this season, as a substitute in their win at Southampton last month.