Kewell returned to Australia at the start of the season when he agreed to sign for Victory, and while he has yet to rediscover the form that once made him one of the Barclays Premier League's best players, he has been contributing consistently to his side.
However, Beauchamp, who plays alongside Kewell for Australia, insists it is another one of the Victory forwards that could pose the bigger threat to Sydney.
"We're not worried about any player individually [but] Archie is always somebody who will always pop up and cause problems," Beauchamp said, according to The Age.
"It would be nice if you could hold on to Archie, I don't think many defenders could because he's a tricky player, but if I can do my job and keep him out, I will be happy."
The 31-year-old centre-back also recognised the threat of Danny Allsopp, but believes Sydney have a good chance of posing a threat to victory if the whole team can do their bit.
"Allsopp is a strong boy as well, but I think individually, and as a team, we need to worry about our own jobs, backing each other up and if we control our own game, it's going to cause them problems," Beauchamp added.
Sydney are currenty 7th in the league on 31 points, while Victory are one spot behind them on 26.