Last Saturday, Ryan Babel probably enjoyed his best moment in a Liverpool shirt. Scoring a long-awaited winner against Manchester United is not enough to put him among the greats of the club, no where near, yet it will be remembered for quite some time.

The manner in which his shot went in may have been blessed by a touch of good fortune yet credit is due for both his positioning and calmness in a situation that could have easily seen the ball hitting those at the back end of the Kop. Babel made what could have been a very difficult shot look easy.

Not the same, however, can be said for most of a Liverpool career which has been complicated by a perplexing case on inconsistency.

Just as telling as the manner of Babel’s goal against United were the circumstances surrounding it. Whilst Steven Gerrard’s introduction on to the pitch was met with the kind of ovations that are reserved for the captain, Babel coming on for Rieira probably made more of a mark on the game and not simply for the goal.

Wes Brown had already had a difficult afternoon trying to contain the Spaniard. With tiredness setting in, he didn’t stand much of a hope for Babel.

That’s how it is most of the time. Of his eleven goals for Liverpool, eight have come as a substitute. And that is indicative of his overall performances with Babel shining when asked to come on late in the game yet struggling when given the full ninety minutes to make his mark.

For a player blessed with so much talent and ability – not to mention one who cost around £14 million - that isn’t enough. This is, after all, a player who Kenny Dalglish predicted would ‘terrify’ players and who has been likened to Thierry Henry.

Shades of Henry are there and not only in Babel’s instinctive predisposition of running at players with the ball at his feet. Henry too had difficulty convincing people about his suitability to play upfront with Juventus playing him on the right hand side of midfield. Then Arsene Wenger stepped in, put Henry up front and neither one ever looked back.

The same could apply for Babel. Even though he was occasionally used in midfield for Ajax, the general acceptance was that he was a striker. It is in that position that he plays for the Dutch Under 21 side and that is where he plays for the senior team as well. At Liverpool, however, he’s yet to be given an opportunity to do so.

That might be at the root of the problem. Benitez clearly feels that by playing out wide Babel will have more of an opportunity to develop. But perhaps that’s not true either: otherwise why would he have gone for David N’Gog to replace Fernando Torres against Aston Villa rather than the much more experienced Babel?

There is another theory, one that finds strength in the rumours that did the rounds at Ajax, according to which, as yet, Babel does not have the mental strength needed to handle top end football. A bad pass, a bad move or even an overcritical fan is enough to unsettle him. When his time on the pitch is brief, that isn’t much of a problem. If he’s on from the start, however, then that’s not the case.

Whatever the reason, the arrival of Albert Rieira puts the heat on Babel. Whereas before Benitez lacked options and often had to turn to Babel by default, that isn’t the case any more.

Unless the player himself is satisfied with bit-part appearances, Babel has to show the determination and consistency needed to win his place in the starting eleven. Otherwise, goals like the one against United will simply serve a reminder of a talent that could have achieved so much yet ultimately failed to do so.