Benitez told Liverpool’s official website: “There are no easy games in football and Birmingham away from home will be a tough game for us.
“Birmingham are playing well in the Championship and towards the top of the table. I know we won 7-0 in the FA Cup but this will be a different game.
“It will be good for Jermaine Pennant to go back to Birmingham and maybe he can score like Craig Bellamy did against his former club when we played Blackburn in the Premiership game.”