Lenny Dykstra's new fight training video shows the ex-MLB has real knockdown power ... because he almost put HIMSELF on the mat throwing a left hook!!!
Nails hit a boxing gym in NYC to train for his upcoming celebrity boxing match against Chris Morgan, AKA Angry Bagel Guy ... and he's working on everything from jabs to power shots.
Lenny is cocky as hell ... and with good reason, he's a former world-class athlete and Bagel Guy ... well, he's just angry.
But, remember, Bagel Guy has been training with legit UFC superstars -- and he's taking the fight very seriously.
So is Lenny from what we're told ... he's been working with Mel Millington, a former Marine-turned-boxing trainer.
Lenny's jabs looked pretty decent but his footwork needs help -- dude almost fell down throwing that hook.
It's all going down Sept. 28 at the Showboat Hotel in Atlantic City -- and Lenny says if/when he pummels Bagel Guy, he wants his NEXT fight to be against Mickey Rourke.
Remember, Dykstra and Rourke have been beefing for years -- they HATE each other -- and since Mickey's taken fights before, it would be real interesting to see those guys beat each other up.