The likes of Ander Herrera and Axel Tuanzebe were all smiles as the players locked hands during a game at the Estadio da Luz.
Mourinho would have been pleased to see Marcos Rojo, who made his name in Portugal before moving to United, take part in the group session following knee ligament damage.
Marcos Rashford and Phil Jones are among those to be all smiles as they train in Portugal
United’s first team stars hold hands as they take part in an exercise at the Estadio da Luz
Axel Tuanzebe (second left) laughs out loud alongside Ander Herrera and Victor Lindelof
Jose Mourinho was also in a cheerful mood as he watched the training session from afar
The Portuguese tactician passes the ball as his players prepare for their European clash
Romelu Lukaku jokes around the Manchester United striker talks to his club team-mates
Manchester United are top of Group A while Benfica are bottom of the group with no points
The versatile defender has been out of action since April 2017 but is now just two weeks away from returning to Mourinho’s starting line-up.
Mourinho said: ‘Rojo is not coming to play but he is coming with the team to train with the group on Tuesday. On Wednesday, individually, but he’s coming [back].
‘I would say, probably in two weeks, Marcos is ready to play. There is no [Eric] Bailly – he was injured in the national team.’
Luke Shaw, who has also been out of Mourinho’s plans due to a lack of fitness, also took part in the session.
The left back played the full 90 minutes for United’s reserve team at the London Stadium against West Ham on Sunday but still made the trip to Lisbon.
United go into the encounter at the top of Group A with Benfica bottom of the group with no points from two games.
Mourinho confirmed he will not end his career at Manchester United due to the nature of modern football.
‘The only thing I said, and it’s true and there was not any misinterpretation, is that I’m not going to end my career at Manchester United.
‘How is it possible in modern football that any manager is going to last 15-20 years in the same club? With the pressure that surrounds every job, Arsene Wenger is the last one.
‘If in this moment I want to finish my career in four or five years, my ambition would be to end my career at Manchester United. I think I’m going to be in football for 15 years and it’s impossible to stay 17 years in the same job. It’s an impossible mission even if you try. Wenger will be the last one
‘That was my answer. I don’t think I’m going to finish my career at Manchester United.’
Manchester United ace Juan Mata heads the ball as he passes to team-mate Jesse Lingard