Lewis moved to his hometown team in March after four years with the Pittsburgh Steeler, and has cemented himself as an important part of the Saints defense, making three interceptions through the first eight weeks.
Payton told Saints.com: "He's been consistent. He has very good length and he's handled the amount of man-to-man we've played, which is quite a bit and done very well.
"There have been games where we put him on certain receivers and other games where we've stayed right and left. I think Keenan has been a real good acquisition for us."
The Saints travel to the 4-4 New York Jets on Sunday.