Blackburn Rovers boss Sam Allardyce will be wary of Everton midfielder Tim Cahill today.

Allardyce feels referee Andre Marriner may need to keep a close eye on Cahill when Everton travel to Ewood Park.

Cahill goes into the game having once again demonstrated his renowned potency from set-pieces on Wednesday night, scoring two headers in the Toffees' 2-2 draw at Aston Villa.

Allardyce is wary of the Australian's aerial threat, but has also questioned Cahill's combative style in the past and stressed that it would be up to the referee to look out for infringements.

Asked whether he thought Cahill had at times used an unfair advantage when attacking balls, Allardyce told Sky Sports News: "Tim Cahill is Tim Cahill - he is a very good player.

"I think that he uses what he has got exceptionally well and it is up to the referee whether he decides he uses it illegally or legally, that's all I'm saying.

"I watched him score two very good goals on Wednesday and he is a very dangerous player.

"I'm not saying he is a dirty player by any stretch of the imagination, but I am saying he uses his strength very cutely and very well indeed.

"We have to keep a close eye on him."