It was a difficult weekend for Mercedes, with Bottas finishing in P3 and Lewis Hamilton a couple of places behind his team-mate in P5. Austria was the first time all season that a race has been won by a non-Mercedes car.
Hakkinen, in his regular Unibet blog, has claimed Bottas' P3 was the "best" Mercedes could have wished for and described the weekend as a "tough" one for the constructors' championship leaders.
"Austria was a tough weekend for Mercedes-Benz due to the challenge of keeping the car's systems cool enough in hot conditions," Hakkinen wrote. "The altitude of the Austrian circuit is almost 700 metres, which reduces aerodynamic downforce. Combined with a track temperature of 56 degrees, this gave Mercedes a headache.
"This meant that Valtteri Bottas and Lewis Hamilton were not able to push as hard as they would have liked, and I think Valtteri's podium finish was as good as they could possibly get.
"It is interesting that Lewis has mentioned the possibility of these overheating problems being repeated at some of the hot European races such as Hungary, and team boss Toto Wolff has admitted these cooling issues are a weak point. You can be sure the team will be doing everything possible to fix this problem."