Eels players have backed veteran centre Michael Jennings to return to form in the final two months of the season after his stint in the Intrust Super Premiership cast doubt over his future at the club.
His demotion to Wentworthville came following the NRL side's heartbreaking two-point loss to St George Illawarra before the round 18 bye.
The veteran centre responded in fashion on the weekend, scoring a try and playing a hand in two more in the Magpies' win over the Warriors in New Zealand.
"He's been great," Mannah said of Jennings' response at training on Wednesday.
"Jenko is all class. The way he's handled the last few weeks has spoken volumes about the character and person he is.
"He handled it well, took it on the chin and went down with a good attitude to New Zealand and put in a great performance.
"We think he's an important part of our team. There were a few weeks there where he wasn't at his best but he looks like himself again now."
Jennings extended his stay at the club until the end of 2019 in June after activating a clause in his contract, but faces uncertainty with Eels coach Brad Arthur drawing a line in the sand with the side's performances after a dismal Telstra Premiership campaign.
The Eels announced during their bye week the signing of Blake Ferguson for three seasons, while the club will make a decision in the coming months on Jarryd Hayne, who is a free agent at season's end.
Mannah hoped Hayne would continue his career in the Blue & Gold.
"He's starting to string together some games now and every game he plays he is growing more in confidence and leadership," Mannah said.
"He was a big part of our strong performance against the Dragons. It's not my decision but I'm always going to be a supporter of having him in the team. I think we're a better team having him there. We'll leave that decision to he and the club."
Meanwhile, Ferguson is averaging 198.6 running metres at the Roosters in 2018 and has been defensively sound on the edge, missing just 13 tackles in 16 appearances.
Parramatta playmaker Mitchell Moses said the signing of Ferguson would ease pressure off the pack next season, who have missed the services of Semi Radradra getting the side on the front foot this year.
"I think that's massive," Moses said.
"He runs 200 metres, has played Origin and for Australia, has done all the things in the game.
"I think he'll be a good asset for us. The way the game has gone at the moment, the back five have to do a lot of work and he gets involved in that side of the game. He can be massive for us next year, but we're just worried about this year."