Trotta, an U19 international, is being tipped for big things by Fulham management.
"He scored a barrel load of goals for the Academy so he just emphasised what we knew he had," McKinlay told fulhamfc.com. "He's got a natural instinct for scoring goals - but he needs to concentrate on more than just the finishing aspect of his game.
"We've got high hopes for him, he scores goals and he got the winner for us in our game against Portsmouth which was pleasing. He always seems to find time and space in the box and get some efforts on goal.
"That aspect of the game comes naturally to him but we need to get him realising that the intensity of the game is what it is. He's got to work hard and make sure he concentrates on his runs and awareness - which will help him become a better all-round team player."