West Ham thrashed Blackburn Rovers 5-1 in the fifth round of the competition on Sunday afternoon and were rewarded with a quarter-final trip to either Shrewsbury Town or Man United.
However, Sullivan is far from enthralled by the prospect of another away tie - and one possibly at Old Trafford.
Sullivan told the West Ham site: "There is no point kidding ourselves that it’s a really tough draw, assuming United beat Shrewsbury as we must assume they will.
"It's hard to comprehend that we are drawn away yet again!"
Gold took to Twitter to slam referee Jonathan Moss's 'mistake' and feels West Ham have a good chance of winning their appeal.
Yes we will appeal Kouyates red card which we believe was a mistake by the referee I think we have a good chance. dg https://t.co/7bngI2DAX1— David Gold (@davidgold) February 21, 2016
Back in the Premier League, West Ham face Sunderland next weekend - which means the return of Sam Allardyce to Upton Park.
Can the Hammers finish strongly in the league and reach Wembley in the FA Cup?