EXCLUSIVE

Comedian Louie Anderson narrowly averted disaster this week at a taping of "Splash" -- because he nearly sank to the bottom of the pool from sheer exhaustion -- but thankfully, Detroit Lions star Ndamukong Suh came to the rescue.

Sources close to the production tell TMZ, Louie -- who's a contestant on the show -- was practicing his dives on Wednesday when he became a little too bushed to pull himself up the ladder ... falling back into the water again and again.

We're told Louie eventually had to be rescued by Suh and divemaster Greg Louganis -- who physically lifted the foundering funnyman to the poolside. Louie then sat coughing up water for several seconds.

Despite the scare, we're told Louie's gonna be fine -- his rep says Louie is already “feeling great, loving the challenge."