Peyton Manning Is Impressed By Dak Prescott

Peyton Manning was impressed by BOTH quarterbacks on the field at the Giants vs. Cowboys game Sunday ... telling TMZ Sports he's "proud" of his brother, Eli, and impressed with Dak Prescott.

Both Mannings -- Peyton and Eli -- were out in NYC Monday morning ... where they both praised the Cowboys quarterback for his play ... even though Dallas lost 20-19.

Despite the expert analysis -- and his guest appearance in the booth during "Thursday Night Football" -- Manning says he's not planning to get into broadcasting.