Kyrie Irving & LeBron James need to beat the hell out of each other immediately ... so says an ex-teammate of LBJ who tells TMZ Sports a healthy dose of fisticuffs can fix the beef.

We got Drew Gooden at LAX, who played with LeBron from '04 - '08 and asked him if there's any way these two NBA titans can put the bad blood behind them and get back to losing to Golden State.

According to Drew there is, and involves some fists, 'cause he told our guy the two men need to just kick the crap out of each other, get all the bad vibes out, and then start over.

There were reports LeBron wanted to do just that, which he refuted, but still, maybe Drew has a point?

Nah, prolly a bad idea ... especially for Kyrie.