PSV moved top of the table with a stunning 4-2 success in the Amsterdam ArenA at the weekend, with Rommedahl playing an instrumental role.
With Ajax having advanced to the second phase of the Champions League, and PSV now devoid of European football, the Danish winger is keen for his team to take full advantage.
"It could be an advantage that Ajax have got to play European matches where they can get tired," said Rommedahl.
"They shall play both weekend matches and midweek matches whilst we shall only play on the weekends.
"But it could also be an advantage for Ajax, in case they gain confidence by pulling off good displays in Europe."
Rommedahl also feels that Sunday's victory over the defending champions is no guarantee, PSV will steal Ajax's crown.
He added to Onside.dk: "It was, of course, fantastic. It was something which we needed purely psychologically. For the self-confidence, it was an important victory.
"But you can't say that we wll be champions due to that win but it will boost us in the coming matches this season."
