France coach Didier Deschamps has praised Anthony Martial for silencing his doubters since moving to Manchester United.

Martial made his France debut against Portugal last month, in the same week that his transfer from Monaco to United made him the most expensive teenager in history.

Numerous eyebrows were raised, with Old Trafford boss Louis van Gaal accused in some quarters of making a 'panic buy' as the transfer deadline loomed, but the 19-year-old has since made a strong impression on the pitch with the Premier League club.

He marked his United debut with a majestic goal in the 3-1 win over rivals Liverpool, following this up with a brace in a 3-2 victory at Southampton.

Martial is now back with his international colleagues for their international friendlies against Armenia and Denmark, with four United goals in seven appearances to his name.

"There was a lot of expectation and criticism initially," Deschamps told a press conference. "He silenced much if not all. 

"I can't talk about how he lives in England, I'm not with him, but he is with us because I feel he has a lot of potential.

"He does not have a strong character. This does not bother me – it is often like this with young players.

"He still has steps to take. Manchester United is not the same world as Monaco."

Martial was part of the United team that suffered a resounding 3-0 loss at Arsenal on Sunday, but striker Olivier Giroud was again restricted to a substitutes' role for Arsenal Wenger's men.

The 29-year-old has started only three of Arsenal's Premier League games this season and was sent off as they crashed to a Champions League defeat at Dinamo Zagreb.

Deschamps has retained Giroud in his squad and is eager to help rebuild the player's confidence on international duty.

"It's a hard time for him," the coach said. "His confidence declined, he left us with a match against Serbia [September’s international friendly], where he could have been much better. 

"At the World Cup we wanted him to start all the games – he did not lose his qualities overnight, but confidence is important."

There are no such concerns over fellow forward Karim Benzema, who made it seven goals in eight matches for Real Madrid this season by opening the scoring in Sunday's Madrid derby.

"If you ask him, he will tell you he always wants to score more," Deschamps added.

"Karim, he scores goals but this is not a poacher. It's not all about scoring goals for him.

"Benzema is someone who likes to participate in the game, he always has."