Xavi believes Louis van Gaal is calmer at Manchester United than he was during his time at Barcelona because there is “less pressure” on him in the Premier League.
Van Gaal has come under fire at points this season following some meek attacking displays from his side.
Despite this, Man United sit fourth in the Premier League, two points behind Manchester City at the summit.
Xavi, who played under van Gaal at Barcelona, backed his former boss to succeed at Old Trafford.
“[He is a] good person, very good trainer,” Xavi said.
“He has a very strong character, but he’s calm in the Premier League because there’s less pressure. He’s much calmer than when he was at Barca or Bayern Munich.
“He’s honest, methodical and a real perfectionist. He’s very demanding, he’s strict and he wants to achieve the highest levels possible.
“After two days of training under him, I thought, ‘Who is this idiot?’ After a week, I thought, ‘He’s right.’ He’ll always be in my heart, Louis van Gaal.”
Van Gaal gave Xavi his first-team debut at Barcelona and the pair enjoy a good relationship. United may be putting in subpar performances this term but there have been a number of young players brought in and it will take time for them to click. The foundations are certainly there and it is clear that United are in a strong position moving forward.