The 29-year-old featured in yesterday's pre-season friendly against the Danish club, but he ended up on the losing side as Liverpool came away with a 2-1 defeat.
The centre-back has been linked with a possible move away from Anfield this summer, but Agger has insisted that he is purely focused on Liverpool for the time being.
According to the Liverpool Echo, when asked if he would be open to returning to Brondby, Agger said: "If the time is right and everything falls into place then I wouldn't rule it out. But the timing has to be right.
"I have thought about it. A lot actually, but I'm here now and that is what I'm focused on."