Olsson featured for Sweden in last night's win over the Three Lions.
"Roy's one of the top, top managers I've had the privilege to work with so I'm not surprised at all that he's unbeaten," he told the WBA website.
"I always think a manager can be great tactically, or in other aspects of the game, but if you don't connect with the person, you won't go 110 per cent for him.
"Roy makes you go that extra percentage.
"I think he has so much experience from coaching national teams, coaching in England, coaching abroad, coaching in Sweden and coaching all over the world, so you know when he says something it's based on experience.
"It's from something he has thought about and developed during his 40 years of coaching experience."