The year is not exactly ending on a high note for Manchester United. Five matches without a win, their longest such stretch since 1998, has seen the club dumped out of the Champions League before the knockout phase and fall six points off the pace in the Premier League. Questions are beginning to be asked about the future of Louis van Gaal, both from the fans, and, according to reports, from the board room.

Such uncertainty may affect Manchester United’s plans in the upcoming January transfer window, but it’s clear that the club has money to strengthen and that there is a strong need to do so. With United having scored just 21 goals in 16 Premier League games this season, there is little doubt where the greatest problem lies.

Here are five players thought likely to be on the radar heading into the reopening of the transfer window.

Riyad Mahrez (Leicester City)

While his Leicester teammate Jamie Vardy has grabbed the headlines, it is Mahrez who has arguably been the top performer across the whole of the Premier League so far this season. The Algerian, who cost just £500,000 when Leicester signed him from Le Havre two years ago, has scored 11 goals and added seven assists in just 15 appearances this campaign. Against Chelsea on Monday, he was the star performer, with his electric dribbling and supreme skill dismantling the Premier League champions. That kind of flair would be a huge boon to a United side that has been desperately lacking in inspiration. Yet with each performance his price will be rising and Leicester’s determination to keep him surely strengthening.

Sadio Mané

After an expected deal for Pedro fell through in the summer, United turned their attention toward Southampton winger Mané, but a move failed to come to fruition. Still, the interest from Old Trafford is thought to remain and the Senegal international could certainly bring a welcome directness to Van Gaal’s team in the final third. Mané, 23, has scored three times and contributed five assists in the Premier League this season. But, having cost in excess of £10 million when signing him from Red Bull Salzburg in the summer of 2014, Southampton would be looking for a substantial fee.

Romelu Lukaku (Everton)

Ditched by Jose Mourinho, Lukaku is continuing to suggest that Chelsea’s decision to sell him to Everton 18 months ago was an incredibly short-sighted one. The powerful Belgian has scored 12 Premier League goals already this season, and is on a run of scoring in six consecutive matches. Still aged only 22, he will surely only continue to improve and develop into a true world-class striker. And Manchester United could really do with one of those right now. With Wayne Rooney appearing in permanent decline and Anthony Martial still raw, a player of Lukaku’s presence and finishing ability could be transformative to United’s chances of landing the Premier League title. Everton, though, have insisted they will not sell any of their star players in January. And it may well take an offer close to double the £28 million that Everton paid for him to even begin to weaken their stance.

Moussa Dembele (Fulham)

Despite already nurturing a young, raw striker, reports have suggested that United are targeting another in the January transfer window. No relation to Tottenham namesake Mousa, Dembele, 19, is a France Under-20 international who has been at Fulham since 2012. It is this season, though, that he has begun to make his mark, firing in nine goals in the English Championship. While there is certainly potential there, it is difficult to see how Dembele would be able to make a major impact at Old Trafford for the remainder of this season.

Edinson Cavani (Paris Saint-Germain)

The linked between Manchester United and Uruguay striker Cavani is nothing new. The former Napoli man’s future at PSG has been repeatedly called into question in recent transfer windows, having registered his discontent at having to play out wide to accommodate Zlatan Ibrahimovic. His strike rate has remained impressive, scoring 10 goals in Ligue 1 this season, however he has an unfortunate habit of failing to take presentable chances in the games that matter most. United may have doubts about paying the £35 million that has been reported as PSG’s asking price, especially as Cavani will turn 29 next February. It also seems unlikely that PSG would be willing to sell in mid-season, especially given that Ibrahimovic is expected to depart at the end of this season.