The Australian international was the subject of a highly-publicised move to The Reds in the close season, with the Elland Road club earning less money than anticipated for the former Leeds trainee.
Kewell has since settled in well with his new team-mates at Anfield and Reid knows he will be a handful to deal with in the lunch-hour kick-off on Merseyside.
The former Manchester City and Sunderland manager was disappointed by Kewell's departure but knows time has moved on and that he must find a way to stop the Australian attacker on Saturday.
"It was obviously disappointing to lose him, and I can understand the reasons, but it's history now," said Reid.
"I just hope he has a quiet day against us.
"You can pick faults with anybody, but you have to give him credit.
"It says it all that Manchester United, Arsenal and Liverpool were in for him over the summer.
"I don't think Alex Ferguson, Arsene Wenger and Gerard Houllier are mugs when it comes to football.
"I'm just concerned as to where he'll play. If Michael Owen is fit, he might play off Emile Heskey, or on the right side, or maybe in a floating role.
"So we'll have to wait and see the make-up of the side and decide then the best way to defend against him."
