Darko is a solid rotation player. He is a good defender, a good rebounder and a solid passer but a poor scorer. He has a positive influence on his team and has done so for several years now.
However, he'll never achieve his potential on a team like the Timberwolves (young, losing team, lack of defensive talent/mentality) so expecting him to show much more than he currently is ... is a losing strategy.
If Minnesota is content with Darko's current contributions, then fine, but if they're expecting improvement ... they need to think again.