Manchester United travel to Anfield this weekend in their first real test of the season. Manchester City, who are level on points with United, have already faced Liverpool and Chelsea, while United haven't played anyone from the usual top four.
Facing Liverpool could give the first real indicator as to whether Jose Mourinho's side can be genuine title contenders this season. The former Chelsea manager has a better record against Liverpool than any other team, but in his first trip to Anfield as United boss, his side left with a 0-0 draw that saw them manage the lowest possession they've had in any match since Opta records began.
Surprisingly, Marouane Fellaini has been Mourinho's go-to man this season. It's not the fact that he has scored four goals thus far, which is four more than Eden Hazard, David Silva and Mesut Ozil combined, but it is his general performances. He's moving the ball on well, making important interceptions and actually starting to look like a half-decent player.
Yet the Belgian will be missing from the Anfield clash after picking up an injury on international duty. Belgium qualified for next summer's World Cup back in September, yet Roberto Martinez still opted to play Fellaini in their recent victory over Bosnia and Herzegovina. The midfielder was substituted with less than half an hour played, thanks to a knee injury.
Martinez asserted that Fellaini would miss only "a couple of weeks," but that would certainly be a speedy return from what could be a serious injury. The club have confirmed that they have yet to assess the injury and how long he will be out.
Ahead of the Bosnia and Herzegovina game, Martinez confirmed that Romelu Lukaku wasn't fully fit and wouldn't be pushed "too hard," yet ahead of Tuesday's fixture against Cyprus, he insisted the striker had recovered from his ankle problem and was "100 percent fit."
On the day it was confirmed that Sadio Mane has been ruled out with a hamstring injury, United fans could breathe a sigh of relief when Lukaku was left out of the starting lineup.
Martinez claimed he hadn't received a phone call from Mourinho dissuading him from using the player, but there's no doubt the United manager would be less than impressed if two of his main men returned from Belgium duty unable to face Liverpool.
"The relationship is very, very good with Manchester United," Martinez said while insisting that Lukaku wanted to play.
It brings back memories of footage seeming to show Lukaku's less-than-impressed reaction to Martinez being named Belgian manager. Sitting on the Everton bench, the camera caught him with his head in his hands before he put his arm around then-club and international teammate Kevin Mirallas.
There's no doubt that Lukaku wants to play for his country. He likely wasn't complaining when Martinez opted to bring him on for the last half-hour against Cyprus, particularly after scoring, to take him within six goals of being Belgium's all-time top scorer. When you consider he's only 24, that's quite a feat.
In 13 appearances for club and country this season, Lukaku has 16 goals. In fact, he has failed to score in only one appearance, which is remarkable.
Yet Liverpool fans have echoed the criticism that has come from their neighbours' mouths, with Everton fans keen to tell everyone that Lukaku doesn't turn up in big games. For United this season, he has already scored in the UEFA Super Cup final against Real Madrid and on his Champions League debut.
In his past two seasons for Everton, he scored a total of seven goals against City, Liverpool, Chelsea and Arsenal, which is a fairly impressive return.
Jurgen Klopp's side have conceded 12 goals in just seven games this season, and Lukaku will be as keen as any striker to take advantage of their defensive weaknesses. You wouldn't bet against him doing it either, having escaped the international break unscathed.