Of course, it's easy to make such statements in hindsight, yet the facts have long been there.
The Blues' record against the league's top seven has been excellent this term, losing just once early in the campaign against Everton.
Outside of that defeat at Goodison Park, Chelsea's record against the top seven stands at 7-3-0.
It's been results elsewhere that have caused the damage to their title hopes—defeats against the likes of Aston Villa and Stoke City or drawing with struggling West Ham United and West Bromwich Albion at Stamford Bridge.
That's where Chelsea's title bid has failed.
In each of those games where points have been dropped, Jose Mourinho has often lamented his team's inability to kill the opposition off. The opportunities have been there, yet Chelsea have lacked the quality in front of goal to make sure of victory.
The pair have plenty in common—notably the fact they made their names at Atletico Madrid, where they proved themselves to be goal machines.
In his two seasons at the Vicente Calderon Stadium prior to joining Monaco last summer, Falcao scored an incredible 70 goals—a figure only bettered by Lionel Messi and Cristiano Ronaldo in La Liga during that time.
Costa's record is just as impressive, with the Brazilian-cum-Spanish striker already notching 33 goals for Atletico this term, adding to the 20 he scored in 2012-13—his first season as regular at the club.
Indeed, their one season together in Madrid last year yielded a combined 54 goals in all competitions, demonstrating the threat Costa and Falcao would pose together as a partnership in the Premier League.
In these times of Financial Fair Play, Mourinho must only choose one. But how do you separate them?
It will be a decision about much more than a player's ability to score goals. Mourinho requires a striker who will arrive as the complete package. With all things considered, Costa edges his ex-teammate in that debate.
Not only is he competing at the highest level right now, the Spanish international is almost three years Falcao's junior. In the modern game, when millions of pounds are exchanging hands for talented stars, that counts for so much.
It's a fact that will weigh heavily on Mourinho when he considers what each player has to offer before making his move.
Costa's relative youth allows him the potential to develop and evolve with this Chelsea team. At 28 years old, Falcao's ability to do that as effectively is severely limited.
Chelsea need only look at Fernando Torres, a striker they signed at age 27 for £50 million who has struggled to adapt to the system in place at Stamford Bridge.
It's been a tough few years, and now on the wrong side of 30, time isn't on Torres' side to turn things around.
Mourinho will be asking himself a whole lot more than questions of age. For instance, how will Falcao recover from the knee injury he suffered in January while on duty for Monaco? It's a major concern, and not because it is threatening his World Cup hopes this summer.
The fee Falcao commands will be close to the record price Chelsea paid for Torres. Transfermarkt currently values him at €60 million. By that assumption, the least the Blues will demand in return is that he is fit for the opening day of the season.
We've seen in the past that anterior cruciate ligament injuries, similar to what Falcao has suffered, can take anywhere between six and nine months for a player to overcome—a point raised by BBC Sport at the time.
By that measure, it could be September before Falcao is ready to play again. Add to it that he will be seeking match fitness and trying to settle in a new country, and suddenly it doesn't look positive.
If Chelsea are making the sort of investment Falcao's signing will require, they cannot take that risk. Regardless of his talents, the money will be best invested elsewhere—namely in attempting to acquire the services of Costa.
While Falcao is spending the remaining weeks of the 2013-14 on the treatment table, Costa is leading Atletico Madrid's charge in La Liga. Meanwhile, his form in the Champions League is giving Los Rojiblancos a realistic chance of at least reaching the semi-final too.
Costa doesn't have the same questions hanging over him as Falcao. He is fit, in form and primed for a transfer that will not only transform his fortunes, but Chelsea's.
Garry Hayes is Bleacher Report's lead Chelsea correspondent and will be following the club from a London base throughout the 2013-14 season. Follow him on Twitter here @garryhayes