The Socceroos defender was released by Leicester City and Aurelio Vidmar has talked with the player.

However Kisnorbo's preference is to remain in England with both Crystal Palace and Ipswich Town thought to be monitoring his situation.

United face another stern test in the build up to the upcoming A-League season when they meet local Super League club MetroStars tonight (Tuesday) at TK Shutter Reserve (Kick-Off 7.30pm ACST).

After defeating Para Hills Knights 1-0 in their opening trial match last week, United coach Aurelio Vidmar will be hoping to see his squad take further steps forward.

Vidmar will have the same squad that tackled Para Hills available for the match against MetroStars, with vice-captain Lucas Pantelis, Brazilian Cassio and midfield duo Fabian Barbiero and Adam Hughes still not being exposed to full match conditions as they recover from light injury niggles.

However, Vidmar has hinted that all four could be a chance to face Raiders in United's next trial match on Tuesday 16 June at State Sports Park.

"We're still about eight weeks away from the first game and that's going to be the bottom line for everyone, that they need to be fit and healthy for Round 1," Vidmar said.

"We've still got a number of games to play before the start of the season so that gives everyone ample time to get at least 3-4 full games in."

For tonight's encounter, Vidmar is set to give two defenders on trial from the Victorian Premier League a run as the club moves to secure the final players in its squad.

Similar to last week against Para Hills, Vidmar will also bring on a number of youth players for the final 30 minutes against MetroStars, giving youth coach Joe Mullen another opportunity to look at possible signings for the Reds' National Youth League roster.

MetroStars, who include former national league players Louis Brain, Ivan Karlovic, Adam van Dommele, Michael Mattricciani, Scott Tunbridge and David Terminello, will be determined to put on a fine display at home after they went down to Campbelltown City in the Super League last weekend, and this should provide the Reds with another firm hit out and more valuable match fitness.

A huge crowd turned out to The Paddocks last Tuesday to watch the Reds take on Para Hills and tonight gives football fans another opportunity to see United in action up close at a suburban ground.

 Kick-Off is at 7.30pm (ACST) and admission is free.