Romelu Lukaku has not done a lot wrong in his first season at Manchester United.
His two goals against Huddersfield on Saturday took his tally to 21. It is the same number as Alvaro Morata and Alexandre Lacazette, two other strikers involved in big transfers last summer, have managed combined. In terms of Premier League goals alone, only five players have got more than Lukaku's 12.
The Belgian has got five assists in the Premier League -- more than Anthony Martial, Juan Mata and Jesse Lingard. Then there is the stuff that statistics don't capture, his work rate in particular.
There is, though, still something missing. More than six months into his United career, Lukaku is yet to answer the questions about whether he can do it in the biggest games.
At Old Trafford, it is not enough just to score goals. They have to be important goals when it really matters.
"He needs a big game against a big team," said Gary Neville after Lukaku's £75 million move from Everton to Old Trafford. "He has to prove that he's a big game player. You have to do that if you're a United centre-forward."
Neville, who played with Eric Cantona, Dwight Yorke, Ruud van Nistelrooy, Wayne Rooney and Cristiano Ronaldo, should know.
Lukaku scored 85 Premier League for West Brom and Everton before arriving at United. But in 57 games against the established big six -- United, Manchester City, Chelsea, Liverpool, Arsenal and Tottenham -- he only managed 15. Of the 25 league goals he scored for Everton last season, 21 came against the bottom 13 teams.
The theory in the summer was that, with better players around him at United, he would begin to turn it around. But, so far, it hasn't happened. Lukaku has scored twice in 12 games against teams in the top 10 this season and is yet to score in 10 games against the top eight.
It has not been a problem for the Premier League's other top goalscorers. Harry Kane has scored against Arsenal, Juventus and Liverpool home and away this season. Jamie Vardy has found the net against United, Arsenal, Chelsea, Tottenham, Manchester City and Liverpool, both home and away. Mohamed Salah has done it against Manchester City, Chelsea, Arsenal home and away and Tottenham home and away.
When United last won the title in 2013, Robin van Persie scored 26 league goals, including against Liverpool home and away, Arsenal home and away, Chelsea, Manchester City and Tottenham. It is the standard United strikers are held to.
Of the 17 Premier League goals Zlatan Ibrahimovic scored last season, nine were against teams in the top 10.
"The centre-forwards of United come under pressure if they do not score," Ryan Giggs said in the summer. "At another club you can go a few games without scoring and it is under the radar. Not at United."
It is the type of scrutiny Lukaku signed up for when he made it clear to Everton that he wanted a move to a bigger club. It is why the chance he missed at Anfield in October and the harder opportunity he squandered at Chelsea in November were replayed again and again.
Against Sevilla on Wednesday night, Alexis Sanchez clipped a ball towards Lukaku at the back post. He tried to take in first time, but blazed his shot over the bar. It was a difficult chance, but United didn't get many others.
Chelsea's visit to Old Trafford on Sunday is another chance for Lukaku to put it right. Even with the title all but gone, it is still an important game.
A win for Antonio Conte's side would move them level on points with United with 10 games to go. After spending so long as City's nearest challengers, the last thing Mourinho wants is to be dragged into a battle for a place in the top four -- especially with the Champions League and the FA Cup to worry about, too.
Mourinho will insist that Lukaku's record in big games is not a problem. During a run of one goal in 12 through October and November, the United manager was quick to point out that goals are not his only responsibility.
"For me, the most important thing is teamwork and he's second-to-none in terms of giving everything he has to the team," he said. "If he scores or doesn't score, that's not a problem."
It is likely Mourniho's response will be something similar if he is asked again this week.
At 24, Lukaku still has plenty of time to get better. But for someone who is obsessed with becoming the best striker in the world, his record in the biggest games is something that will have to change.
He will get another opportunity against Chelsea this weekend.