Stellan Skarsgard insists Shia LaBeouf's bad boy reputation shouldn't ''cast any shadow over him as an artist''.

The 66-year-old actor has starred alongside the 31 year old in two movies - 'Nymphomaniac' and the upcoming 'Borg vs McEnroe' - and Skarsgard said that LaBeouf landed the role of John McEnroe because he is very good at his job.

Skarsgard thinks that LaBeouf's well-documented problems with alcohol stem from the experiences of his childhood, during which he witnessed his father Jeffrey take drugs and struggle with alcoholism.

Speaking to The Guardian newspaper, Skarsgard said: ''I totally understand the choice, but I think it's right not because of Shia's personality, but because of his skills. I mean he has had problems when he gets drunk, probably he can't handle it or whatever. And that has to do with his childhood and the things that he hasn't solved in his life. It shouldn't cast any shadow over him as an artist. There are some artists that are a**holes but are straight all the time and I despise them.''

'Borg vs McEnroe' has been helmed by Danish filmmaker Janus Metz Pedersen and follows the story of the rivalry between Swedish tennis player Bjorn Borg (Sverrir Gudnason) and American McEnroe (LaBeouf) which ends with a showdown at the 1980 Wimbledon final.

Although having a successful career in Sweden before moving over the America, Skarsgard has starred in some of Hollywood's biggest movies including 'Mamma Mia', 'Thor' and 'Good Will Hunting', and said he received more praise from American directors than in Sweden.

He said: ''The first time I worked in America, in one month I got more praise form the director than I had in 10 years in Sweden. That was not because I was 10 times as good. Most good directors, I have this feeling, had something weird about their childhood. They had very little social contact when they were small. They were all sitting in their room creating fantasy worlds, and they don't want to abandon that control. They're all control freaks, one way or another.''