As Marion’s Jimmy “The Tooth” Manning prepares for what he hopes to be his fifth-straight professional MMA victory on Saturday, he’s been propelled by a little extra motivation.

Just two weeks ago, his main training partner and best friend since their childhood days, Matt Sherman, passed away unexpectedly.

“We lost our quarterback,” Manning said. “It’s been really tough. I’ve stayed focused. I’ve trained twice as hard for this one and everybody is going to see the best Jimmy Manning they’ve seen in the cage.”

Sherman — who was Manning’s quarterback at Old Rochester in the mid-1990s under Matt’s father, coach Craig Sherman, and went on to play at New Hampshire — had a training room in his basement that Manning and another former Bulldog football player, Aaron Zell, would frequently use when Manning couldn’t make the trip to his regular gym, South Shore Sportfighting, a 50-minute drive away in Norwell.

“He was into the training, into fight nights,” said Manning. “He’d look up things on my opponent. He was a very big part of my professional and amateur career. He’ll be in there with me.”

Manning’s fifth professional fight will be Saturday during Cage Titans 35 at Memorial Hall in Plymouth. Doors open at 5 p.m.

The 40-year-old Manning, who is ranked as the No. 14 lightweight in New England and the No. 47 lightweight in the U.S. Northeast by Tapology, will look to improve on his 4-0 pro record against his most experienced opponent to date: Fernando Perez (7-15). None of his previous opponents had more than eight fights under their belt.

“I’ve seen him fight a couple times,” Manning said. “He’s a good, solid fighter. He’s good everywhere. He has good striking, good Muay Thai, decent wrestling. We’re both brown belts in jiu jitsu.”

Manning will benefit from being back to his normal weight class. After opening his pro career with a win over Ryan DiBarolomeo at 150 pounds on Nov. 5, 2016, Manning beat David McClendon at 155 pounds on Jan. 28, then jumped up to 165 to beat Kevin Schroder on April 8 before bulking up to 175 pounds to beat Montoyia Swilling on June 17 at Cage Titans 34.

“It’s going to be good,” Manning said. “I don’t have to mess around with catch weights. It’ll be nice to be getting used to regular plans with dieting and getting some normalcy with my weight. It’s less stress.”

After winning in Cage Titans 31, 32, 33 and 34, Manning originally planned on skipping 35 as he works toward his ultimate goal: A bout in Las Vegas. But after a brief respite in Florida, he decided to get back in the octagon.

“I tried to take time off and I wanted to work toward my black belt in jiu jitsu, but I have to strike while the iron is hot,” he said. “I have good momentum and I don’t want to lose that.”

At 40 years old, Manning isn’t fooling himself into thinking his title belt window isn’t closing rapidly. He’s seen first hand how quickly life can change.

“Having (Sherman) pass as abruptly as he did, that’s going to give me a little something extra,” Manning said. “It’s definitely going to be in my memory. He’ll be in there with me. I’m ready to die in there. This is my life now.”

Follow Brendan Kurie on Twitter @BrendanKurieSCT