The 28-year-old has one year remaining on his existing deal with the Blues, with the Liga giants poised to swoop for his signature when the summer transfer window reopens.
Speaking after Chelsea's 0-0 draw at Leicester on the final day of the Premier League season, Hazard revealed he has already made a final decision regarding his future and is just waiting for the club to sanction his departure .
Chelsea may not be able to bring in the mercurial attacker's replacement if a FIFA imposed transfer ban takes effect in June and Di Matteo feels the club's legal woes may prevent a major deal from happening.
The Italian coach, who led the Blues to Champions League glory in 2012, has suggested Hazard's exit is far from certain at this stage, despite any desire he may have to move on.
"It would be a real shame for any club to lose a top player like Hazard," Di Matteo told Sky Sports .
"But I don't think it will be as easy as that because if you take into account the transfer ban Chelsea have, I'm not sure they are going to let anyone leave easily that they don't want to.
"It's understandable that there might be some intention from him to have a different experience at a different club and in a different league after many years at Chelsea.
"But he's got a contract and, at the end, I guess they'll have to sit down and see what solution they can find."
Maurizio Sarri is also still on course for a trophy at the end of his debut season at the helm, with a Europa League final against Arsenal to look forward to on May 29 .
The showpiece event could mark Hazard's farewell appearance for the Blues, as talks over a possible €130m (£122m/$146m) deal with Real Madrid remain ongoing.