Matic joined Manchester United from Chelsea for £40million in the summer transfer window.
The Serbia international has helped Jose Mourinho’s side to level on points with rivals Manchester City after seven games this term.
Gale was asked which midfielder he has been impressed with the most since the resumption in August.
His answer was Matic and he says he cannot understand why Chelsea let him go.
“I’ll go for Matic because simply he’s made the biggest difference,” Gale said on Sky Sports.
“Obviously there are more creative central midfield players around and everybody will go to the flare ones.
“But in terms of the importance to Manchester United, he’s the one for me.
“And believe it or not, although he does give that defensive solidity to them in front of the back four, he can see a pass as well.
“Because he’s six-foot four, maybe a little bit gangly, people don’t think he’s got that ability, but he has.
“So for me, it has to be Matic.
“He’s made the big difference for Man United.
“Why Chelsea sold him, I haven’t got a clue.”