Edinson Cavani a far cry from Falcao, and could be the No 9 Man Utd have been craving

It was an easy comparison to make.

Radamel Falcao was the last South American striker to sign for United, and many believed upon arrival at Old Trafford that his best days were behind him.

However, in just 129 Premier League minutes for his new club, evergreen Edinson Cavani has three goals, one less than Falcao managed in 26 league appearances. Instantly, Cavani and Falcao appear very much to be chalk and cheese.

Despite Falcao being much younger than Cavani when he signed, the gulf in fitness between the two appears to be more of a chasm. Falcao was plagued with knee problems during his time in England, but Cavani, thanks to his surprising passion for ballet, is in prime condition, even at 33.

Having that extra yard or two still in the legs, combined with Cavani's worldly striker's brain, is a deadly combination, as Southampton discovered to their peril at St Mary's on Sunday.

United had played reasonably well for much of the first half, and created chances, but some poor finishing, and James Ward-Prowse's set-piece prowess, left United staring down the barrel of another, damaging defeat.

The panacea to their profligacy in front of goal, however, did not even have his boots tied as the game restarted for the second half, but that represented a brief reprieve for Saints, as Cavani put on a striking display you simply cannot teach, and one United have been lacking since another veteran loanee - Zlatan Imbrahimovic - departed.

United have high hopes for Anthony Martial as a central striker, and after his most prolific season to date last time out, it appeared he could finally kick on and fulfil his promise at Old Trafford.

However, this season, Martial is without a league goal, and remarkably for a United forward, has had just three efforts at goal from five starts, seven fewer than Harry Maguire. In a fraction of the time, Cavani has showed more of what United are looking for from their strike focal point, and some.

Before he found his scoring touch, Cavani brilliantly set up Bruno Fernandes to get United in it, before showing a level of alertness the very best strikers are born with to head United level. Then, when United needed that final touch to their comeback, Cavani was on hand with a super header again. Fresh and alert, even in the dying embers of the match.

"He is a number nine who wants to be in between the posts, he is always on the move, he wants to get in front of you," Ole Gunnar Solskjaer said after the match.

In the first half, without a real recognised central striker, Fernandes often found himself as a False 9, with Mason Greenwood and Marcus Rashford in wider positions. That is not where you want your most creative force to be. Where he is most effective, however, is with someone to aim at, and with Cavani ahead of him, someone who instinctively knows where to be, Fernandes, frighteningly for opponents, could become even more productive.

In truth, after his impressive display from the start in the Champions League in midweek, Cavani should have started at St Mary's. You can understand Solskjaer's thinking - two starts in a row for a 33-year-old is quite some going - but this is no ordinary 33-year-old.

The doubters were out in force when he signed, but even after a just a handful of appearances it is becoming increasingly likely that those who believed United were foolish to turn to Cavani as their only summer strike addition may be forced to each their words.