Jose Mourinho has challenged Henrikh Mkhitaryan to become the creative force in Manchester United's Premier League title bid, with sources telling ESPN FC that the manager believes the Armenia international must do more in games against the club's top six rivals.

Mkhitaryan, 28, overcame a difficult start at United last season following his transfer from Borussia Dortmund to play a key role in the team's successful Europa League campaign.

The midfielder scored six goals as United won the trophy for the first time, including one in the 2-0 victory against Ajax in the final.

But despite Mkhitaryan starting this season in the first-team as United moved top of the table with three successive wins, Mourinho still harbours doubts over the player's ability to influence games against the likes of Manchester City, Liverpool and Chelsea.

Sources have told ESPN FC that while Mourinho has been impressed by Mkhitaryan's start to the season, which has seen him create five goals in three games, he wants the former Shakhtar Donetsk midfielder to raise his game to another level when United face their title rivals.

Jose Mourinho wants Henrikh Mkhitaryan to become Manchester United's creative force. John Peters/Man Utd via Getty Images

The United manager was disappointed by Mkhitaryan's contribution and performances against the top four last season, with the player scoring just once in that sequence of games, during the 1-0 win against Tottenham at Old Trafford.

Mourinho is hopeful, though, that an extended run in the starting XI will boost Mkhitaryan's confidence and importance to the team before United face Liverpool in the first of their meetings with a title rival on Oct. 14.

Mkhitaryan told ESPN FC during United's preseason tour of the United States that his job this season was to create the chances for Romelu Lukaku to score and he has already teed up two goals for the Belgium international.

Mourinho now wants him to prove he can do it against more powerful teams in the league, however.