Manchester United manager Louis van Gaal has to take one major lesson on board from Wednesday's hugely disappointing first-half performance against Burnley, star strike duo Radamel Falcao and Robin van Persie just can't play together.
On paper it looked like a match made in heaven for United fans, proven world-class forwards with an understanding of what it takes to succeed at the very highest level.
Van Gaal clearly thought the same and even moved captain Wayne Rooney back to a deeper midfield position to accommodate the experienced duo, but teamwork has not made the dream work at Old Trafford and one of Van Persie or Falcao must be dropped as a matter of urgency, if not both.
Burnley game was the final straw
If any United fans who didn't watch the Burnley game think criticism of Van Persie, Falcao or the pair as a strike partnership is harsh please reconsider, because the statistics from that 3-1 victory make it clear there's just no chemistry between the two.
Falcao failed to have a single shot at goal against a side fighting for their lives, while Van Persie managed just one effort himself and that was from the penalty spot.
Criticism over a lack of creativity should also be levelled at both, because they managed to carve out just two chances for team-mates all game and also attempted to beat a defender just once apiece.
Lack of physical presence also a problem
Van Gaal's much-discussed 'long balls' forward also don't work with Falcao and Van Persie leading the line, as showed by the Burnley match.
With the Red Devils desperately lacking penetration in a dull first 45 minutes against the Clarets attempts to be more direct didn't work and Van Persie and Falcao must take their share of the blame for that.
Between them the duo contested 18 aerial duels on the night and managed to win only five. Neither Van Persie or Falcao have aerial prowess as a unique selling point on their considerable CV's, but in a two-man forward line at least one player simply has to make the ball stick and give United the platform to build attacks more quickly.
Van Gaal has been at pains to defend his strategy and insist Rooney's long-term future lies in midfield, but his theory just doesn't match up to statistics which go well beyond the Burnley performance.
Goal return can't hide flaws
On the surface Van Persie has at least found the back of the net consistently to justify his place in the starting XI, currently United's top scorer with 10 goals in 23 Premier League games.
Van Persie's performances have been well below par though, particularly when partnered with Falcao.
In 11 starts alongside Falcao the Dutchman has found the target only five times, which is some drop-off from previous seasons for United featuring 30 and 18 goals respectively.
United's star strikers aren't completely to blame and it's clear there's a lack of service in a side created by Van Gaal that lacks genuine wide play or penetration in the final third, but they are part of the problem not the solution as a pair.
Falcao looks a shadow of his former self
Van Gaal is highly unlikely to drop Van Persie given the special relationship he shares with a man who was his captain at the World Cup for Holland, so in the best interests of the team as a whole maybe its time to put Falcao back on the bench.
Falcao's five-month spell at United has been hugely frustrating to say the least, with a player ravaged by injury over the last 12 months once again struggling to stay match fit and prove he deserves an eye-watering £265,000-a-week pay packet.
Injury problems have been no excuse in recent weeks though, with Falcao starting eight of United's last nine Premier League games. In that time he's managed to score just three times and missed gilt-edged chances that in past years would have been taken, with the late miss from six yards against West Ham United the most prominent example.
Put Rooney back up front
Van Gaal has surely ruled out sanctioning a permanent £43m move for Falcao this summer based on his efforts in 18 games for United, which means its time to admit his first-choice strike partnership is dead in the water and put Rooney back in his best position.
Even a promotion to more regular starts for James Wilson would be more beneficial for United, in both the short and long-term.
Wilson may be raw and untested but would bring more pace, purpose and endeavour to United's front line than Van Persie and Falcao put together on current form.
United are in such a precarious position when it comes to finishing in the top four that the madness of sticking with Van Persie and Falcao cannot be allowed to continue, its time for a positive change in the final third or the Red Devils are at serious risk of missing out on Champions League football for the second season running.
Manchester United fans, are you happy to stick with Van Persie and Falcao in attack, or do you agree its time for a major change? Let us know by having your say in the comment box below!