Ole Gunnar Solskjaer conceded David de Gea should have saved Mason Mount's goal but stood by the player.
David de Gea had one huge mistake and an overall underwhelming performance as Manchester United went down 1-3 to Chelsea in the FA Cup semi-final.
Chelsea's victory moved Frank Lampard a step closer to silverware in his first season in charge of the club where he earned legendary status as a player.
Chelsea beat Manchester United 3-1 at Wembley on Sunday and will face London rivals Arsenal in the FA Cup final on August 1.
Ole Gunnar Solskjaer says he has never considered dropping David de Gea "for a one second" as the Spanish goalkeeper prepares to make his 400th appearance for Manchester United.
David de Gea was heavily criticised by former Manchester United skipper Roy Keane for letting Steven Bergwijn's shot slip through his fingers in the previous match against Spurs.
There was controversy over VAR as Everton held Manchester United to a 1-1 draw at Goodison Park.
Goals from Virgil Van Dijk and Mohamed Salah gave Liverpool a 2-0 win over rival Manchester United.
Premiers League: Already struggling Manchester United were dealt another huge blow as their two key players Paul Pogba and David de Gea were ruled out of the Liverpool clash.
David de Gea, who had been linked with a return to Spain with Real Madrid for several seasons, has put pen to paper on a new four-year deal with Manchester United.
Paul Pogba, who has been linked with a move to Juventus and Real Madrid, starred in Manchester United's dominant first-half.
David De Gea is in the last year of his contract and has been linked with French champions Paris Saint-Germain.
David de Gea is so far holding out in contract negotiations to prolong his current deal beyond the summer of 2020.
Jose Mourinho said he wanted David de Gea to stay, and he remains optimistic an agreement on the player's will be reached.
Spain face a tough challenge to reach the FIFA World Cup 2018 knockout as the 2010 champions take on eliminated Morocco in their Group B clash at Kaliningrad Stadium on Monday.
Spain would be desperately seeking three points in their World Cup Group B match with Iran after being held by Portugal.
Iran are sitting on top of the World Cup Group B team standings and Spain would like to change that.