WWE's Bobby Lashley Volunteers to Fight Shawne Merriman If Batista Won't

Great news for Shawne Merriman ... if Batista is too busy to take him up on his fight offer, there's another WWE superstar willing to take his place -- Bobby Lashley!!!

As we previously reported .... the ex-NFL All-Pro linebacker is getting into the MMA game with his own promotion, Lights Out Xtreme Fighting ... and called out Dave freakin' Bautista for a fight in the process.

TMZ Sports spoke to Lashley about the potential matchup ... and while he thinks that's cool and all, Bobby's got a better opponent in mind ... himself!!!

"Shawne Merriman, if he wanted to do it, sure. Call me up. I'll train, I'll fight. I would do it."

Look, Bobby ain't a scrub -- not only is he a wrestling champ, but he's also got a 15-2 career record in MMA.

So ... you still think this is a good idea, Shawne???