Lukaku scored his 13th goal of the campaign during Saturday's 2-1 victory over Swansea to keep alive Albion's hopes of securing a European spot.
And Morrison insists Albion should pull out all the stops to try and get the on-loan Chelsea striker back at The Hawthorns next term.
Morrison knows the 19-year-old will leave a big hole to fill should he be recalled by the Blues next season.
Morrison said: "Romelu's goals are one of the reasons we are where we are. Hopefully the club can get the deal sorted. He is a pleasure to have and I think he will be even better next season.
"Will he benefit from another season at West Brom? Definitely. You think how young he is for such a big unit.
"He's got a lot of hard work to go but I'm sure he is going to be a top player. I'm sure Chelsea are going to develop him.
"He is big and strong and scores goals and is quick and powerful. He is a handful for anyone."
Morrison also believes Albion will need to strengthen their squad if they qualify for Europe.
He said: "We will need some players in if we are going to (play in Europe).
"You saw what we were like in December and January when we couldn't pick a win up (through players missing).
"Probably the manager will realise that and hopefully we can get there and build a squad for it."