The best signing Jose Mourinho will make all summer?

Jose Mourinho is typically as active as any manager during the transfer periods, and this summer has proved to be no different.

With the Chelsea boss already securing moves for Spanish teammates Cesc Fabregas and Diego Costa from FC Barcelona and Atletico Madrid, respectively, Mourinho has helped bolster an attack that needed a boost of energy. Centre back Kurt Zouma has also been brought in after spending last season on loan with Saint Etienne.

Already gone from last year’s squad are Frank Lampard, the 36-year-old all-time leading goal scorer who had been at Stamford Bridge since 2001 until the club parted ways with their midfielder last month, and David Luiz, who moved to Paris Saint-Germain for a massive £50m.

It appears that at least three other key players, Demba Ba, Ashley Cole and Samuel Eto’o, could be on the move as well, and no one can say for certain what the future holds for the much-malgined Fernando Torres now that his fellow countrymen have been brought aboard. Ditto for longtime keeper Petr Cech now that Thibaut Courtois is set to finally make his Chelsea debut after three years spent on loan at Atletico.

It doesn’t look like Mourinho is finished making moves, either. Rumours have been swirling around that the likes of Filipe Luis, Angel di Maria, Paul Pogba and Rafael Varane (just to name a few) will find their way to Stamford Bridge before next season kicks off.

But the easiest, and arguably most logical choice Mourinho can make is for someone that the club has neglected for the last two years despite already being on the Blues’ books.

Chelsea has become something of a a mini version of the Belgium national team, with winger Eden Hazard starring for them for the last two years and Courtois joining him next season.

Yet there is one more Belgian eager to prove many doubters wrong who believe he is not fit to line up at Stamford Bridge.

Romelu Lukaku signed with Chelsea in 2011 at the ripe age of 18 after spending the previous two seasons with Anderlecht. He appeared in just 10 games in that first season with the club and was unhappy with his lack of playing time.

Rather than try and develop him themselves, Chelsea sent him out on loan, first to West Brom in 2012 and then to Everton last season. He was highly productive in both seasons, netting 17 goals for West Brom and 15 for Everton.

Now 21, Lukaku appears ready to follow in his idol’s (Didier Drogba) footsteps and become a star for Mourinho.

Many of the maturity issues that plagued him at an early age appear to have gone away, as evidence from his response to being benched for Belgium’s Round of 16 World Cup match against the US by scoring an extra time goal that gave them a 2-0 lead.

There does not appear to be as much of a logjam up top for Chelsea even with the arrival of Costa, and Lukaku is talented enough to be the second striker for Mourinho and could even make sense in the starting squad, depending on the formation.

Plus, he appears to have great chemistry with Hazard, a player Mourinho and the rest of Chelsea are so committed to keeping happy and productive after handing him the #10 jersey for next season after Juan Mata’s departure.

Bringing Lukaku back to Stamford Bridge would also negate the need for Mourinho to pay a transfer fee for someone else’s striker.

So the reasons for Lukaku going back to Chelsea are there. It makes a great deal of sense in many ways, but the rest falls on Mourinho, and no one knows for certain what he will decide to do.