The Colombian arrived from Feyenoord in the summer, but has not lived up to the hype so far.
With 23 goals in 49 games for the Dutch club, fans were expecting similar returns at Elland Road.
However, fans can look to his time at Feyenoord to see that he does take time to settle into new surroundings.
"Yes, I always knew I had the potential to achieve what I have achieved now. In the first year I just had to be patient," Sinisterra revealed in an interview with Feyenoord's official magazine.
"There was a group that got the trainer's confidence, so I had to wait for my chance, although I didn't know when it would come.
"In the meantime I had to get used to life in the Netherlands, the language, the food, you name it. In retrospect, I am grateful for what happened then, because it made me stronger.
"I have always continued to invest in myself, you should eventually reap the benefits of that. I think I did that last season."