Why Manchester United stay does not add up for Falcao

 COMMENT: The Colombian is determined to make permanent his loan stay at Old Trafford but will know that his current output is not enough to justify what would be a huge outlay

Radamel Falcao is smart enough to know that the maths does not add up for Manchester United when his current form is weighed against the cost of signing him permanently in the summer.

The Colombian has scored just three goals in 13 appearances for United since his loan move from Monaco on the final day of the summer transfer window - and he must fear that he will be sent back to the principality at the end of the season.

United have agreed a deal to make Falcao's move permanent for €56 million but it would be ludicrous to exercise that option - in addition to a €306,000-a-week salary package - while the 28-year-old is so out of sorts.

The primary reason why Falcao moved to United on loan in the first place revolved around concerns about the serious knee injury that forced him to miss the second half of last season and the World Cup.

The €8m loan fee was seen as a calculated gamble by United executives after several rounds of talks with his representative, Jorge Mendes, but Falcao started slowly and was hampered but niggling injuries including the calf problem that restricted his appearances in October and November.

*Premier League stats Louis van Gaal has continually appeared to talk down Falcao, whether complaining about his lack of fitness or suggesting that he depends on the form of his team-mates.

Falcao insists that he is now 100 per cent fit and has scored twice in United's last four league fixtures but he must maintain that level of return for the remainder of the season if he wants to stay at Old Trafford.

Which he does. The former Porto and Atletico Madrid man has made it clear that he intends to be at the club beyond this season and is playing for his future.

"From my point of view, yes, I want to stay but obviously I have to analyse the situation," Falcao said in December.

"I'll see if I play more and see what decision the board takes but, from my point of view, I really want to stay."

But can he rediscover the sort of form that saw him score 72 goals in 87 matches for Porto and 70 in 90 appearances for Atletico Madrid?

He turns 29 in February so United can reasonably anticipate that his productivity will decline over the course of a long-term contract, although he displayed his famed predatory instincts for his recent goals against Aston Villa and Stoke.

The Red Devils' upcoming fixtures would seem to offer an opportunity for Falcao to hit his stride and consistently deliver. They face Southampton on Sunday before games against QPR, Cambridge United and Leicester City in the remainder of January.

United sources say that Falcao is an outstanding professional and excellent in training but he needs to produce more in a red shirt to justify another huge outlay for the club on the back of last summer's €190m spending spree.

It is not like Falcao can complain about a lack of service when he is joined in the United attack by Robin van Persie, Wayne Rooney, Angel Di Maria and Juan Mata.

As it stands, Van Gaal might reflect that he would be better off showing more faith in youngster James Wilson or signing a cheaper alternative to Falcao next summer. That would free funds to sign a top-class central defender and central midfielder, two areas in which the Dutchman is desperate to improve his team next season, particularly with extra fixtures from their anticipated return to European competition.

These are the scenarios which United will be analysing when they decide whether or not to pull the trigger on the option for a €56m permanent transfer that he already been agreed and signed.

At the moment, Falcao's chances of staying at the club look bleak. He needs to quickly get back to his best and make the maths work in his favour.