Harry Kewell's barely played an hour of soccer in six months, but Western Sydney coach Tony Popovic still considers him a threat.

The veteran striker is set to feature for Melbourne Heart in Friday night's clash with the Wanderers for the first time since being subbed off during the opening A-League round with a whiplash injury.

While the 34-year-old is not a confirmed starter, Heart chief executive Scott Munn has admitted Kewell's inclusion would make a world of difference.

And Popovic isn't ready to write off his former Socceroos teammate.

"He's a class player," Popovic said.

"We don't know whether he'll play or not - but if he does, we expect to see Harry (bring) his quality on the field.

"We'll be prepared for that and we'll do our very best to try and nullify him.

"I don't know what kind of shape he's in - I think that's a question for Melbourne Heart.

"But we'll just prepare ourselves for this game, for Melbourne Heart and also try and improve on and build on what we're doing."

The Wanderers remain undefeated after four rounds with two draws and two wins to their name, but Popovic insists it's still too early in the season to get carried away with their results.

The Heart, on the other hand, are winless with back-to-back losses following two draws.

"We certainly don't take anyone lightly and we never have, and we'll show Melbourne Heart the utmost respect," the manager said.

Veteran striker Brendon Santalab joined his coach in downplaying both their own good form and their opponents' recent poor showings.

"We've started well - undefeated after four games, which is fantastic. But we face a new challenge this week," he said.

"They're on the bottom of the table but it's no indication of where they're at."

Wanderers winger Youssouf Hersi, who missed last Friday's 2-1 win over Adelaide United with a foot injury, remains in doubt for the AAMI Park match, with Popovic labelling him a "day by day proposition".