Borussia Dortmund ace Raphaël Guerreiro has hit out at a German football Twitter page, after the account posted Tweets making allegations over the player's mistreatment of the club's staff.

German Football Daily, while reporting a roundup of club related news, claimed that the left-back had demanded that the Bundesliga side's staff performed duties outwith their responsibilities - such as running errands. 

It is unclear whether there is any substance to the rumours surrounding the Portuguese international, who won the 2016 European Championship with his country two years ago. Guerreiro has struggled for first team football with BVB this season, as Jeremy Toljan and youngster Dan-Axel Zagadou have kept him out of the starting lineup.

The 24-year-old - who was born in France - started his career with Ligue 2 side Caen, before being snapped up by Ligue 1 side Lorient the following season. After spending three impressive seasons with Les Merlus, BVB bought the versatile player for £9.5m last season, and played as a central midfielder during the reign of Thomas Tuchel.

In other news, BVB have reportedly set their sights on signing Celtic starlet Kristoffer Ajer. The 19-year-old has become a pivotal part of Brendan Rodger's side, and already has two full senior caps for Norway. Ajer has played extensively for the Glasgow side in Europe this season, and put in a star performance in his team's 1-0 Europa League win over Zenit.