Thelin is a coach who exudes a calmness no matter the situation.
The Swede never once looked like getting carried away during Aberdeen's storming start to the season, nor has he looked at all panicked during this recent winless run.
This performance must have been a concern, though. His side offered nothing in attack, looked nervous at the back and were second best in pretty much every individual battle.
All the purpose and conviction of the opening months of the season was missing in Aberdeen's play.
Graeme Shinnie and Jamie McGrath were unable to exert any meaningful influence in midfield. The attacking players failed to make any sort of impression.
The only piece of goalmouth action Duk saw was to clear a Wales first-half effort off his own line.
Other than Mitov, who made a string of good saves to keep the scoreline down, it's hard to think of a single Aberdeen player who would receive pass marks.
If this slump is not to become a full-blown crisis, this side will need to pick up very quickly.