Cesc Fabregas is making Antonio Conte think harder and harder, with each substitute and FA Cup appearance, to find a way to accommodate him in an already in-form Chelsea side.
The creative midfielder has only started five of his side's league games, yet ranks seventh in the entire division for assists, finding regular football only in knockout competitions.
He has directly contributed to Chelsea's points total with a key goal against Sunderland, while his last-minute assist against Watford secured all three points in August.
Fabregas' six decisive passes have helped Chelsea forge a nine-point gap at the top of the table, with a 30-yard pass to Diego Costa against Manchester City ranking as the best - and one of the most important - of the lot.
In recent weeks, he has demolished lower-league opposition in the FA Cup, resulting in Conte looking to him before anyone when he is chasing game. The 29-year-old came on against both Liverpool and Tottenham as the Italian threw everything at his rivals in an attempt to claim a victory.
Against Hull, Fabregas was immediately effective. His team-mates were struggling, but the former Barcelona man's pin-point cross found the head of Gary Cahill. This was part of a performance in which he completed all of his passes and created two chances.
Increasingly, he has shown a tenacious side to his game. He looks fitter than ever and four bookings already show his willingness to commit himself fully to the defensive cause.
His mischief was at the centre of Manchester City's explosion in their 3-1 defeat at the hands of Chelsea in December - as he found himself at the centre of a fracas that saw two opposing players sent off.
Conte knows that Fabregas continues to guarantee creativity, but in the deep position he prefers Nemanja Matic is first choice with N'Golo Kante acting as the box-to-box player.
Still, the Spain international's displays have forced Conte to consider a 3-5-2 formation, which would allow him to use the ex-Arsenal player on a more regular basis.
101 - Only Ryan Giggs (162) and Frank Lampard (102) have provided more PL assists than Cesc Fabregas (101, level with W Rooney). Conductor. — OptaJoe (@OptaJoe) January 22, 2017
The system was the bedrock of Juventus' success under the coach and saw Andrea Pirlo deployed in a deep playmaking role, as Fabregas will for the Blues. However, there is one major problem: it means dropping two from the key attacking quartet of Diego Costa, Eden Hazard, Willian and Pedro.
Chelsea were smart not to sell Fabregas in January, as his lack of action means a lower value. He has reminded the world of his true qualities in recent weeks, and such is his level he can aspire to move to another elite side, and not a declining AC Milan. And that's if he wants to go at all.
His darkest hour came against Arsenal earlier this season, when he was hauled off in the 54th minute as his side were overran at the Emirates, but that already seems a distant memory.
On Saturday, Fabregas has another date with the Gunners, and whether he starts or is on the bench, they will fear him. He is not used to being a substitute and he is one of the world's most decorated players, but he has continued to succeed, despite being written off.
He has a World Cup, two European Championships, as well as every domestic honour in Spain and England, and if Chelsea are to add another Premier League crown to their trophy cabinet, he will be a key weapon for Conte.