The former Hammer is in Italy where he currently plays for Lazio but he has showed he still cares for his old side after tweeting a message to them.
That is despite leaving under a cloud when he was dumped by former boss Sam Allardyce after a string of discipline issues in East London.
Morrison still cares
Morrison sealed hero status with West Ham fans when he scored one of the goals of the season on the way to a memorable 3-0 win at White Hart Lane back in the 2013/14 season.
And he is hoping Slaven Bilic's side can get one over on their North London adversaries again, even if he can't be involved this time.
Posting on social networking site Twitter, Morrison said: "Good luck today West Ham, lead the way on Twitter get behind the team."
The post also included a string of hammer emoticons book-ended by two love hears and a fist of respect.
How different things could have been
It will leave some West Ham fans wondering what might have been just over two years on from Morrison's wonderful solo goal at the Lane.
His fall from grace under Allardyce, though, was almost as spectacular as his Maradona-esque run and finish that day.
Watching this big derby won't do those feelings any good as the talented midfielder will no doubt be thinking how different his career could have panned out after that goal.