Jesus Perez felt Adam Lallana deserved his goal against Burnley at the end of a difficult week.
Lallana has been in the headlines as a result of the complaint made by Saints against referee Mark Clattenburg for comments made to the Saints midfielder in the defeat at Everton.
It has led to Lallana being put in the spotlight, even though it was the club rather than the player that filed an official complaint.
Lallana was called upon as a second half sub in the FA Cup tie against Burnley and scored a great goal as Saints made it through to the fourth round with a 4-3 victory.
Perez, assistant manager to Mauricio Pochettino, said: “I think everyone can see Adam Lallana this season and every single minute he is on the pitch he tries to do his best and is always doing great, great things.
“He deserved it because of the example for the squad, daily on the training ground, and it’s no surprise for me when Adam Lallana on the pitch is doing things and goals like he did.”
Perez confirmed that injuries to Rickie Lambert and Gaston Ramirez were not serious and added: “It was a strange game but you know in the cup game everything is possible because the teams are playing without pressure.
“Sometimes one of the sides is clinical and the other not so much and I think that was the case.
“At the end of the day the most important thing is stay in the next round, especially when you play a cup game at the end of a tough period like Christmas was for us and I’m just happy for that.”