"If the situation remains the same over the next few months, and I'm not getting more time in the middle, I will not want to continue as a Liverpool player," he told Israel's Channel Five TV station.
"The fact that I have spent so much time on the bench, while there has been a winning formula on the pitch, tells you everything.
"I hope it changes for me, because I want to stay and prove myself, but it won't be easy. I know I'm at one of the biggest clubs in the world, and that there are many good players like Ryan Babel and Jermaine Pennant who sometimes aren't even in the squad, but it's not much fun sitting on the bench all the time.
"I always wanted to prove myself good enough for Liverpool, and I thought I did well last season to contribute so many goals and assists. But there seems to be more competition for places this time, and if I continue to be on the sidelines, I would not want to stay, even though it is Liverpool.
"Maybe I will have to accept that and start learning another language, such as Italian or French or even Russian."