Well, I guess you can say that he's a late developer. He left the Swedish league just 2 years ago, but started to score goals for fun the second he arrived at Groningen. There were some talk about him leaving last summer, with Ajax interested, but it didn't happen. I can't see him staying this summer, but I don't think he's top class just yet, even though there's real potential.
Keni; Marcus Rosenberg hasn't been very good the last couple of years, and he's 4 years older than Berg, so I've given up hope on him.