Ross Barkley is perhaps the most frustrating Premier League player to watch.
When he's good, he's really very good. When he's poor, he's...well, really very poor. Time after time, the midfielder follows up a performance full of vigour and energy with one where you forget he's even on the pitch.
It's slightly baffling that at 26 and with that talent he undeniably possesses, Barkley is yet to make a significant impact in the Premier League.
But after showing signs that he may be on an upward curve again, can he finally step out of his own shadow in the remaining weeks of the season?
As far as his Chelsea career goes, this is probably his last chance saloon.
Barkley had a dream start to his career, setting the Premier League alight with several key performances in his first full season for Everton, aged just 19. In April 2014, he was nominated for the PFA Young Player of the Year award, and received the same nod two years later.
England legend Gary Lineker said he was "a star in the making and a prodigious talent" and his then manager Roberto Martinez named him as "the best young England talent I have ever seen, for sure".
But like so many other English talents of that era, injuries and the pressure and scrutiny of being a homegrown star took its toll.
He somewhat bravely took the eventual decision to seek a fresh challenge with Chelsea in 2018, where he first struggled for minutes under Antonio Conte, and later his creative licence was restricted under the meticulous Maurizio Sarri.
Having worked his way back into favour last summer, Barkley's debut season under Frank Lampard didn't get off to the greatest of starts. He missed a penalty in a crucial Champions League clash with Valencia, while off the field he was pictured dancing topless in a Dubai nightclub in November. Lampard spoke at the time, insinuating that Barkley needed to show better professionalism and dedication if he is to become a key player at Stamford Bridge.
Barkley clearly heard the call, as since returning from injury in March he has found a new lease of life, suddenly dictating attacking moves and driving into the box with all the confidence and flare we saw from him as a teenager.
He has become something of a knockout specialist, scoring in three out of four rounds of this year's FA Cup, including a wonderful solo effort against Premier League champions Liverpool before lockdown, and the winner on Sunday against Leicester in the quarter finals.
Despite the upturn in attacking returns, he hasn't scored a Premier League goal since October 2018 - a worrying statistic for a player of his quality. But goals in the league aren't far away, especially if he can transfer his recent cup form over.
Crucially, Lampard is a manager who doesn't pick on reputation or what has gone before. He picks on performance and he has been careful but reassuring in his appraisal of the Englishman since his return to form.
"I played with Ross and I know he’s a great lad. He wants to be the best player he can be and has a great attitude in that sense," the Chelsea boss said, speaking to the club website. "He shouldn’t get caught up in where he’s at, what he may be, what may have been, only how he trains every day.
"When you see that you see he’s a really good player for us and can be that goalscoring midfielder, and not only that: he can play, he can run, he can tackle, he can do a lot of things. His shooting, right and left foot, is as good technically as I see on the training pitch."
Playing with Barkley during his time as a player and occupying a similar midfield position himself, Lampard is better placed than most to understand where the footfalls in Barkley's game lie and what he has to do to correct them.
But what is also clear is that Lampard, while supportive of homegrown talent, will replace players if they do not meet the grade - you only have to look at the substitutions he made at half time on Sunday to see that. The difference for Barkley is that he is no longer in that category. He doesn't have time to 'come good', he should be there already.
It isn't going to get any easier either, with the impending big name arrivals this summer and the club's rumoured interest in Kai Havertz, who could quite feasibly sweep in and take his place in the side. Only Barkley himself will know if he has the hunger to stay and fight for his place, but right here, right now, he is delivering and providing Lampard with a vital goalscoring midfield option.
The question for Barkley is: does he have the strength of character and the hunger to sustain this form and confidence and become the player we all thought he could be?
We might get an answer in the coming weeks.