Louis van Gaal warned Adnan Januzaj that he must improve his all-round game after the Manchester United winger scored the only goal at Aston Villa on Friday in his first start since February.
United manager Van Gaal this week stressed that there is no way Januzaj will be allowed to leave Old Trafford amid reported interest from Sunderland.
Belgium international Januzaj was a surprise inclusion in United's starting line-up for the trip to Villa Park and repaid the faith shown in him by scoring his first Premier League goal since April 2014.
The 20-year-old showed great composure and skill to turn sharply inside Micah Richards and find the far corner of the net with a first-half finish which took a deflection to ensure United made it two Premier League wins out of two.
Speaking after the game Januzaj responded to transfer talk by telling Sky Sports: "It was only rumours, I'm happy here and of course I'm going to fight for my place."
Van Gaal reacted by stating that the youngster will only feature for the first team on a regular basis if he contributes more.
"He scored a wonderful goal, but all the other aspects of football you have to show. I'm pleased because with this goal we have won, but there is more than scoring a goal," the former Netherlands coach told Sky Sports.
He added: "There were a lot of unnecessary ball losses [from Januzaj]. Also from Memphis (Depay), a lot of ball losses and that's why there were not a lot of chances."
Van Gaal was delighted to follow up the win over Tottenham on the opening day by securing another three points, but knows his new-look United side are far from being the finished article.
He added: "The start to the season is better than last year, but that is not so difficult. We had one point at this stage and now we have six, so I am very happy.
"There is still a long way to go. You cannot expect it with only four weeks' preparation. You need more matches to come in the form I think we can show."
