Willian joined Chelsea in 2013 as a cult hero thanks to having a medical at Tottenham Hotspur then signing with the Blues anyway. It took him a while to be properly embraced as a footballer, despite a wonder strike against Norwich on his league debut. But since he beat first Juan Mata then André Schürrle to a starting berth, he’s fit in to the team like he was born to it.

Willian is the definition of a team player. When he first came, there were concerns about how he would adapt to the physicality of the League; doubts allayed by the fact that he’s quite physical for his stature. Just ask Gael Clichy, who’s still trying to get up after Willian barged into him in the build up to Remy’s goal against Manchester City. Willian is blazing quick and he rounds that off with very good balance, agility and a work-rate that can only be matched (or bettered) by Ramires.

Positionally, he’s versatile. Willian has played every position in Chelsea’s attacking band with very good results, and that’s because he blends his physical superiority with technical brilliance. The Brazilian is excellent with the ball at his feet and his passing is also superb. It is these features that allow him to lose neither the ball nor his composure in the tightest situations, often picking good close passes or dribbling and accelerating out of tough spots. When he gets the chance, his shooting can be good although, as his goal record might suggest, it’s a bit hit and miss.

To cap it all off Willian, is defensively diligent, and uses his physical gifts to track back and press effectively. His tackling, not particularly strong when he first arrive, has improved greatly since he started playing under Jose Mourinho.

What’s currently holding Willian back is way he chooses to use his well-rounded abilities. For someone so gifted, he doesn’t carry anywhere near the direct threat to goal that one might expect. He’s capable of playing great passes and scoring great goals, but rarely attempts do do either. Instead, he has a tendency to be conservative in attacking play, mostly going for the safest option. He can and should be far more explosive than he has been so far for Chelsea.

There are signs, however, that he’s getting there.

Last season, Willian started taking steps towards becoming the player that perhaps he’s meant to be, adding a little more attacking threat to his game. This improvement was especially marked in the second half, and saw him easily see off the nominal competition Juan Cuadrado provided for a starting spot as well as a welcome buffer to both Oscar and Cesc Fabregas’ dips in form.

Normally, when Chelsea are having problems, Eden Hazard has to carry the weight on his own. But to everyone’s surprise, Willian stepped up too, using his gifts with much more purpose and being more of nuisance to defenders. He ran at them, went past them, combined with team mates and looked to create chances more often than previously with Chelsea. His consistency was also markedly improved - the number of poor games he had last season can be counted on one hand.

Chelsea’s style of play last can be best described as “adaptive”. In different matches, against different opposition, they played in different ways. Primarily, however, the team is set-up to press opponents high up the pitch, win the ball and immediately go on the attack. Willian is extremely important in this rapid, high-pressure counterattacking game as well as in traditional buildup play.

Unlike most defensively-minded wingers, Willian’s response to Chelsea losing the ball tends to be to drop back to maintain the team’s defensive shape. That means he’s deeper than the other attacking midfieders, and when possession is retrieved he serves as a conduit to link the ball back to the forwards, while also serving as a solid defensive presence.  When Chelsea have the ball, the Brazilian usually drifts inside and helps to keep the ball moving and circulating. It is rare to see a Chelsea build up that does not include a Willian touch. He is everywhere, using his technical and passing ability to combine with teammates and drifting inside to help stretch opposing defences.

The value of a player that contributes to every facet of a teams play cannot be overstated. Willian is as adaptive as Chelsea, contributing in different ways to different situations. His work is what allows the likes of Fabregas, Hazard and Diego Costa to flourish. The fact that he has started making strides to improve his attacking threat is a mouth-watering prospect.

To reach the next level, however, he has to start scoring or assisting more often. Given his role and position in this team that might be problematic. It’s difficult (ask Oscar!) to manage both a serious defensive role and get on the scoresheet with any consistency, but even when in a freer role, like he was with Shakhtar Donetsk or Anzhi Makhachkala, Willian didn’t score much more often than he has so far at Chelsea.

But  there are many ways a player can be dangerous without scoring or assisting. Watching Andres Iniesta in his pomp is testament to that - his direct contribution to his team’s production look small after the fact but simply watching him play demonstrates just how important he is. If Willian can start using the space he gets even a little more effectively, it would go a long way — being a potentially dangerous player can be as effective as being an actually dangerous one, taking heat off teammates and allowing them to thrive.

Willian must find the balance between risk and safety. His priority is of course to maintain the team’s stability, but chances to express himself on the attack are too frequently ignored. Fix that, and he moves from a very useful system player to a Chelsea star in his own right.