IF you think Sir Alex Ferguson has got problems trying to replace Roy Keane then spare a thought for Arsene Wenger, who may soon be saying goodbye to Thierry Henry.

If some of the stories in the national press are to be believed then Henry could be heading for Spain and Barcelona come the end of the season, which would be a total disaster for everyone connected with Arsenal Football Club.

At the moment, the flamboyant Frenchman has got to be one of the best strikers in the world, if not THE best judging by the he continues to terrorise Premiership defences.

Two more stunning goals against plucky Wigan on Saturday underlined Henry's true value to the Gunners and, while they are by no means a one-man team, I think it's fair to say they are only half the force they can be when the Frenchman isn't in their starting line-up.

At his best, Henry is simply unstoppable and no-one else in the Premiership can hold a candle to him, with the exception of, maybe, Wayne Rooney.

He's got everything you'd want in a modern day striker; explosive pace, an amazing eye for a goal, incredible touch and awesome confidence in his own ability.

When he puts his mind to it, there is nothing he cannot do with a football, which is why he's priceless to Arsenal and Arsene Wenger.

If, as seems increasingly likely, he were to join Barca next summer then exactly how would Mr Wenger go about trying to replace the irreplaceable?

Unlike Keane, who is past his best, Henry is performing at the peak of his powers and even £50 million wouldn't be adequate compensation for losing such an influential player.

This weekend, Mark Hughes and Blackburn Rovers must somehow find a way of stopping him if they are to remember their last ever league visit to Highbury for all the right reasons.

I'm sure Mark will instruct his players to defend that little bit deeper, with the plan being to limit the space in behind the back four for Henry to run into.

The lads in midfield and upfront must also work hard to stop the supply at its source because if Henry gets a run on a defender then that's when he really hurts you.

And, as Wigan found to their cost last week, Rovers must also avoid giving away unnecessary free kicks on the edge of the box at all costs.

If they do all that, and take their opportunities when they come along, then they might just pull off a famous victory and add to Wenger's problems.