Romelu Lukaku has the chance to improve his record against the top teams

Romelu Lukaku has answered every question so far but Manchester United's trip to Liverpool is a new test. Can he do it at a top-six rival?

They said he missed chances but he has scored more than anyone. They said his first touch was not good enough but the ball seems to end up in the net enough of the time. The second touch has usually been the one to put the ball away. The next question asked of Romelu Lukaku is about his big-game record. So will the answer be similarly emphatic?

Firstly, the facts. Lukaku's stats against the so-called 'big six' sides are not particularly impressive. Overall, he has 15 goals in 57 appearances but it has deteriorated in recent years. Since his permanent move to Everton, he has one in six against Saturday's opponents Liverpool and his return against other top-six opponents in that period is even worse.

Lukaku's goalscoring record against the biggest clubs needs to improve

Lukaku has scored five goals in 35 games against the top six since that 2014/15 season. It is a one-in-seven record largely explained by a 15-game streak lasting 17 months in which he failed to find the net once against the strongest sides in the Premier League. It was an issue that was widely reported at the time, but perhaps some context is required.

Lukaku has been playing for Everton not Manchester United. Any striker would be expected to score more regularly against weaker opposition than against the strongest. That situation is exacerbated when part of a team that has not won a Merseyside derby at Anfield this century and not won one anywhere since Lukaku's Anderlecht days.

On the other hand, this disadvantage has not stopped Bournemouth's Josh King matching Lukaku's total in a fraction of the games. Leicester's Jamie Vardy has already scored against Arsenal, Chelsea and Liverpool this season alone. In the same period in which Lukaku has found the net five times against the top six, Vardy has 19 goals against those opponents.

Jose Mourinho on why he cannot rest Lukaku until Zlatan Ibrahimovic returns Jose Mourinho on why he cannot rest Lukaku until Zlatan Ibrahimovic returns

It is a contrast partly explained by Vardy's peculiar characteristics. It suits him to play against teams who dominate the ball because he can use his pace to expose their high line on the counter-attack. Perhaps Lukaku prefers it when the openings come closer to the opponents' goal with bodies up in support. Even so, it is enough to raise concerns.

"He is incredibly talented and I have seen him destroy defences," Sky Sports pundit and former Manchester United favourite Gary Neville noted on Twitter in the summer before adding the caveat. "He went missing in too many matches I saw but with a better team and players around him he has an improved chance to deliver in big matches."

There have been chances in those games. Lukaku's five goals came from 78 shots in 3111 minutes. But he can expect more opportunities at United. "I knew that he would score more goals for us than for Everton or West Bromwich Albion," claimed Jose Mourinho recently. "That's logic. But I wasn't expecting him to be, match after match, putting the ball in the net."

Lukaku has scored seven in seven for United. In a sense, this is the flip side of his struggles against the top teams. During the period in which he scored five in 35 against the big six, he also scored 48 times in his 75 games against the other teams in the Premier League. So far it has been enough to ensure that Zlatan Ibrahimovic has not been missed at Old Trafford.

But there is still that nagging doubt; the knowledge that Ibrahimovic delivered for Manchester United when it mattered. Twice he went to Wembley last season - in the Community Shield against Leicester and in the EFL Cup against Southampton - and twice the veteran striker came up with the late winner to secure the trophy for United.

Ibrahimovic was also the last man to score for the club against Liverpool - getting a late equaliser at Old Trafford in January. The six-pointers will have added significance this season as Mourinho's men chase the title. Lukaku has already shown how important he can be in beating the rest. The final challenge of doing it against the best now awaits.