As reported by Tribal Football last week, Chelsea has a deal agreed with United over a permanent transfer worth £22-25M but there is every chance the club will send Sancho back to Old Trafford at the end of the season due to his dire form. He has just two goals and three assists in 25 games under manager Enzo Maresca as he continues to underperform.
Gallas, who played for Chelsea from 2001 to 2006 has been ruthless in his assessment of the young winger and believes he should be sent back to the Red Devils if his form does not start to improve.
"Did you see him dribble past his left-back today? No. He did nothing," the Frenchman told Stadium Astro.
"He didn't challenge his left-back opponent. He always gets the ball, does some skills, and then passes the ball back. We want to see more, especially when you are the winger.
"That player has talent. He's a talented player, everybody knows this, but we don't know why he can't perform and can't show what he can do. At Dortmund, he was magnificent. At Manchester United, it didn't work well for him. He came to Chelsea, and at the beginning, we saw that Sancho from Dortmund, but then he disappeared.
"I don't know what the problem is, but at the moment, he can't stay at Chelsea because he has to do more. When you play in the Premier League, you have to play every game at the highest level. It's not easy, but you can't just play well for a few games and then chill out."
The Blues slipped to their eighth Premier League defeat of the season at the Emirates Stadium which did not help Sancho’s case for staying in West London. As football enters an international break it may be the perfect time for Sancho to rest and refocus over the break as he looks to bounce back before the end of the campaign.