New Portsmouth boss Tony Adams wants his 42-year-old former Gunners team-mate to join him at Fratton Park.
Keown said: “It was a very tempting offer and one I had to think hard about.
“But I just don’t feel it’s the right time for me to go back into the game.
“It was very flattering to be asked and I have no doubt that Tony will be a big success.
“What the offer has done is rekindle my passion to get back into the game but I have only recently retired and am happy focusing on my media work.”
