The Lions beat the top-flight club 3-0 and now face an anxious wait ahead of a Lewisham Council meeting on Wednesday about the sale of land around The Den.
The council is expected to confirm plans to sell the land to property developers Renewal and Millwall have warned they could be forced to relocate to Kent if that happens.
Bournemouth boss Eddie Howe made 11 changes for the third-round tie on Saturday and opposite number Neil Harris says he sensed an shock.
“We guessed that Bournemouth would make changes, because they have got a big few games coming up in the Premier League.”
Harris wants a home draw after goals from Steve Morison, Shaun Cummings and Shane Ferguson beat Bournemouth.
Millwall face Charlton in League One on Saturday and Harris says he would swap the win against Bournemouth for three points at The Valley.
“That is how big it is,” said the Millwall manager.
