The twice Double-winning centre-half, who was the first to predict Henry's return to north London, can't wait for his old team-mate to get stuck into Leeds United tomorrow evening.
"He has been magnificent against Leeds in the past," Keown told the Sunday Mirror. "It will be a treat for the fans, the manager and the player himself. It's like being transported back in time - a fantasy come true for everyone.
"He may be a bit slower. And it might not be till the end of the two-month loan that we see glimpses of what he did before.
"But I think his return will restore Arsenal's pride. It will energise Arsene Wenger and he'll be a huge influence on the young stars such as Jack Wilshere and Theo Walcott. Theo idolises him. It could certainly galvanise the team into winning a trophy."