Seedorf's men will visit the Spanish capital on March 11 hoping to overturn a 1-0 deficit from their UEFA Champions League last 16 first leg and the former Dutch midfielder believes Ancelotti - Real Madrid's head coach - will help him plot the downfall of Atletico.
Not only are Atletico the local rivals of Ancelotti's current employers, the 54-year-old Italian also coached Milan for eight years.
Seedorf was one of Ancelotti's players from 2002-2009 when they won Serie A, the Coppa Italia and the Champions League (twice).
"We bumped into each other today and had a bit of a chat," Seedorf told Sky Sport Italia on Tuesday.
"The (Madrid) derby (on Sunday) was a great battle, especially in the first half.
"I won't have second thoughts about calling Carlo for any information."
Ancelotti believes Atletico are the favourites to progress to the quarter-finals of the Champions League ahead of Milan.
"I wish Seedorf a lot of luck, even though Atletico are the favourites. It will take a big effort from Milan," Ancelotti said.
"It will be an intense game because Atletico will give everything. For them, reaching the quarter-finals is a big goal and there will be a great atmosphere.
"We will need to see the best Milan."
