The London club ran out 3-0 winners despite a close first half and the Englishman claims the Portuguese manager told his players they were doing well.
Shaw was the one United player who performed admirably throughout the match and was their one saving grace.
Mourinho must be pleased with his left-back but completely let down by the rest of his players following the loss.
Fans may never know what he said at full-time but the youngster has revealed what he said at half-time when the score was level.
According to Manchester Evening news, Luke said: “We spoke at half-time and Jose said they hadn’t had one corner, one cross or one dangerous opportunity.
“Then, from their first corner in the second-half they had a goal [from Harry Kane], but even then we should have been relaxed because it was only one goal and we still had a lot of time.
“But then came another mistake, another silly, stupid goal. We were so on top and it is just really disappointing, everyone in the dressing room is really sad, especially after the first half we had.”
Poor defending certainly costed the Red Devils once again and they’ve already conceded seven times in three games.
Jose’s players have hardly looked like a solid defensive unit but they’ve been lacking attacking wise as well.
It’s only been three matches into the season but some fans are already calling for the former Real Madrid manager to be sacked.
Whatever happens in the end, Mourinho will definitely feel he could’ve done more with a side that includes the likes of Romelu Lukaku, Alexis Sanchez and Paul Pogba.