Shawne Merriman says the Chargers knocked it out of the park with their Jim Harbaugh hire ... telling TMZ Sports he believes his ex-team now has a feeling of, "'Hey, we can go out and win a championship now!'"
The former pass rusher was fired up when we spoke with him shortly after the Bolts named the ex-Michigan coach their new head man ... explaining to us he thinks L.A. is now a real-deal Super Bowl contender.
Merriman says the roster Harbaugh is inheriting is "the most talented team to never make the playoffs" ... and he's expecting a turnaround to happen relatively swiftly.
"If I'm Jim Harbaugh, I'm licking my chops," Merriman said. "I'm walking in there one day like somebody just handed me the keys to a Ferrari and I'm about to slam on the gas, right?"
As for the fit, Merriman previously expressed concerns about Harbaugh's ability to connect with young players at 60 years old ... but it seems those qualms have been squashed since the hiring process officially kicked off a few weeks ago.
"It's just a match made in heaven," he said. "I don't think there could've been more of a perfect storm."
Merriman also expressed gratitude that his former team passed on the opportunity to sign Bill Belichick ... believing the fit just wouldn't have worked in the City of Angels.
Meanwhile, as Merriman waits for the Harbaugh tenure to formally begin later this year ... he's got his hands full with his Lights Out Xtreme Fighting league, which is set to host a major event on Feb. 16 -- one that Merriman says Harbaugh will definitely get free tickets to if he wants 'em!