Rob Lowe Says Peyton Manning's Got A Future In Comedy

There's a new comedy star on the horizon ... and according to Rob Lowe this guy can also throw a mean spiral ... 'cause Rob thinks Peyton Manning could have a future in the ha-ha game.

Manning is set to make his big debut on "Modern Family" soon ... but first honed his chops as part of Rob's celebrity roast on Comedy Central earlier this year.

We got Lowe leaving Madeo ... and asked if he thought Manning -- who also has appeared in a TON of funny commercials and hosted 'SNL' -- has any shot of being the next Adam Sandler (circa 1999).