However, he has now scored four times in the last five games and is expected to hold down a regular starting place for the next few weeks at least as Tuncay is sidelined with a knee ligament injury for at least a month.
"I have made mistakes in my career with some of my moves. I didn't stay and fight for my position," he has said.
"Now I have to learn from the past and think that it is not always an option to go somewhere else when I am not in the team.
"Sometimes you have to test yourself. You have to do everything you can to earn yourself a position in the starting 11.
"At certain moments I was very close to leaving Middlesbrough.
"But when I spoke to the manager I was told that I was part of his plans and he wanted me to stay.
"I have had several clubs, that's true, but maybe it's time for me to face the problems and fight for my position.
"I am staying at Middlesbrough and I will see whether it will work or not.
"But I have worked very hard to try to make it work. I have spent the whole summer working on my fitness and I think I am starting to see the benefits now.
"The manager told me that I might not start the first three or four games of the season.
"I was happy with that because Tuncay and Afonso Alves finished last season very strongly and they deserved to be in the team.
"But every time I came off the bench I tried to do my best and I scored goals.
"There is no point being on the bench just for the sake of coming on and being on the pitch.
"When I came on I wanted to impress the manager and the supporters and try to score goals.
"The supporters at Middlesbrough have always been great to me and when you have the fans behind you, you must always do whatever you can to stay in the team.
"Losing Tuncay through injury is a big loss to the team because he is a great player and he has done so much for us," he added.
"But I don't look at it that I am in the team because Tuncay is injured.
"I have done well when I have been given opportunities and I think that I am in the starting line-up because of what I have achieved.
"But you have to do well in every game if you want to stay in the team."