"I am not happy not playing because I am here to play," Shittu told Kick Off Nigeria.
"I came here to play football and that is why I am still working hard every day in training to make sure I get a chance to play because that's the plan when I came here.
"My plan is still the same. It hasn't changed.
"That's why I am not happy that I don't get to play regularly even though I believe I have done well each time I have been given a chance."
Asked about rumours he could leave the club, he added: "I have a lot of respect for this football club so I don't want to say anything right now.
"The important thing is that I am here now, and I believe I am doing my best to get into the team."