But that is no longer the case after Real Madrid offered him a three-year-contract on Tuesday agreeing to pay the Spanish FA £1.75m in compensation.
Lopetegui is a big fan of De Gea and will likely start the 27-year-old in all of Spain's games in Russian Federation this summer.
Lopetegui will go head-to-head with Cristiano Ronaldo at the tournament, with Spain set to take on Portugal in their opening group game this Friday.
And it comes just three days before the 2010 World Cup winners begin their campaign in Russian Federation, as they face Portugal in Sochi on Friday.
"But if you look at it from the point of view of Real Madrid, there weren't really many alternatives out there, and you are talking about somebody who has a brilliant record with the national side".
In addition, he remains something of an unknown quantity as a coach.
Lopetegui took over Spain in July 2016 after Vicente del Bosque retired from the role.
He previously had a spell as manager of Porto, as well as with the Spanish national youth team set-up and at Real's B team. At the very highest level, however, he is still somewhat untried.
However, they have now made a decision to appoint Lopetegui, who is currently concentrating on managing Spain in Russian Federation.
Some commentators have defended the timing of Lopetegui's appointment but others believe it will put a strain on relationships between Real Madrid and Barcelona players in the squad.