The two sides meet in the final on Sunday, with Klopp eyeing his first trophy since arriving at Anfield in October.
In contrast, Pellegrini is looking to end his reign at City on a high, with him set to leave the club in the summer after they agreed a deal for Pep Guardiola to take charge in the summer.
And when asked who the trophy is more important for, Merson answered that it is Klopp who needs the success more of the two managers.
“I would say Jurgen Klopp,” he told Soccer Saturday.
“Players will come to Liverpool next season on the strength of this. It’s going to be hard to get players to Liverpool next season because they’re not going to be in the Champions League, unless they win the Europa League.”
“I think it’s a massive game for Liverpool. Win this trophy and you would look at them and think, surely it would push them on.”
Aside from helping to attract players to the club in the summer, winning the trophy could also be the springboard Liverpool need to further success.
They will be confident of winning the game though, with a 4-1 win over City earlier in the campaign the perfect template for further success this time around.
That was arguably their best display under Klopp since he took charge, and he will be hoping his side can recreate it and secure his first piece of silverware in England.