Full-back problem needs to be sorted by Benitez

The fact is, Liverpool fell short in Europe because, as is the case in the Premiership, they do not have the squad to cope when the going gets really tough.

Weaknesses in both full-back positions have been apparent all season long with Riise, in particular, being no more than an accident waiting to happen for far too long.

Contrast Liverpool's full-backs with those at their fellow English Champions League semi-finalists and the gulf in quality verges on the gargantuan.

Since marshalling Lionel Messi superbly on his Liverpool debut, Alvaro Arbeloa has done little to convince that he has a long term future at Anfield.

Steve Finnan has been an excellent servant to the club since joining from Fulham five years ago, but the Irishman is now out of favour with Benitez having failed to convince when called upon this season.

On the opposite flank, Riise's form has bordered on the abject for so long that you have to really dredge the memory banks to recall what it was that made him a fans' favourite in his early years with Liverpool.

And, though technically gifted, Aurelio cannot be relied upon to play week in, week out, simply because his body cannot stand up to such rigours.

Between them, Liverpool's four full-backs cost a grand total of £9.5m or, to put it in starker terms, around half of what Manchester United and Chelsea paid for their midweek right backs.

Michael Essien and Owen Hargreaves might both be central midfielders by trade but their quality levels and sheer versatility allows them to slot in on the right side of defence without undermining their teams in other departments.

Both Steven Gerrard and Jamie Carragher could do a better job at right back than those who have spent much of the season there for Liverpool, but if either of them were shifted from their usual slots it would leave the Reds short in other key areas.

And, anyway, what's the point of taking two of your best players out of their preferred positions just to make up for the shortcomings of others?

The solution to this problem does not lie within the current Liverpool squad, it lies elsewhere, and that is why when Benitez goes shopping this summer a pair of top quality full-backs must be at the top of his list.

A deal to sign Swiss international right back Philipp Degen is all but concluded, but whether or not he is the man to take Liverpool forward has to be open to question.

Injuries have taken their toll on Degen's ability to become a first team regular at Borussia Dortmund and his CV does not exactly glitter.

In his early years as a professional, scouts flocked to see him play for the Swiss Under-21s and when Dortmund won the race for his signature it was considered quite a coup.

But Degen's potential remains unfulfilled and his signing is a risk if Benitez considers him any more than a useful auxiliary member of his squad.

Liverpool are not far away from United and Chelsea. If you look at the spines of all three sides, Benitez's stands comparison with pretty much anything Alex Ferguson and Avram Grant can select.

Pepe Reina, Carragher, Martin Skrtel, Daniel Agger (when fit), Javier Mascherano, Xabi Alonso, Steven Gerrard and Fernando Torres is a formidable backbone and gives the Reds boss something tangible to build upon.

But unless their quality is matched on the flanks, "if only" will be Liverpool's mantra for some time to come.