The West Ham co-owner still has a big soft spot for the target man.
Indeed, Carroll has been praised as a 'very special player' and is expected to play a 'big role' for the rest of the season.
And Sullivan said in his regular 'From the Boardroom' column on the West Ham site: "It was great to see Andy Carroll back on the scoresheet on Saturday and he made a big impact scoring a goal and having one cleared off the line.
"It showed us all what a very special player he is and hopefully he can play a big role for us in the final stages of the season."
The comments show a massive soft spot for the Hammers striker and, no matter how well Dimitri Payet, Manuel Lanzini, Diafra Sakho and more do, it seems Sullivan and David Gold will always will Carroll on to succeed more than anyone.
The West Ham striker certainly made an impact at Chelsea and offers a valuable option few other top teams have.
Other strong sides do have target men but don't cross well enough to use them. So Carroll can be a great impact sub and perfect for certain games.
As a regular starter, though, Carroll doesn't look like he has the fitness or consistency to be as effective. There have been games this term, for instance, when the 27-year-old has started to the detriment of Slaven Bilic's men.