Keown believes Walker is a player of quality that has 'slipped back' since his early Tottenham days.
For England, meanwhile, Keown thinks Southampton's Nathaniel Clyne has certainly overtaken him as first choice while he has been out injured.
Giving both sides of the argument, however, the pundit also said the Southampton man will be looking over his shoulder now that Walker has returned to fitness.
"He [Walker] is a talented player and had a fantastic breakthrough season at Spurs but has slipped back since." the former Arsenal defender said during a 'Tackle Keown' session on the Daily Mail website.
"He might suit Mauricio Pochettino’s style but there are others there who are competing for his place.
"For England, he has certainly been replaced by Nathaniel Clyne but there is always room for a player with the quality he has. Clyne will definitely be looking over his shoulder now."
Southampton are currently fifth in the Premier League table, with Pochettino's Tottenham five places behind in 10th.