"This is the final year of his contract but I don't think it will be his last season because he's capable of playing on," Benitez told liverpoolfc.tv.
"He is a fantastic player, a very good professional, a very nice person and is clever.
"He knows it is very important for him to play the right number of games because he knows then he can play maybe more years.
"Physically he is one of the best players in the squad. I'm not talking about pace, but physical condition.
"He knows that he can have a future at the end of the season. It depends on him really. If he can do the right things, then I wouldn't have any problems (with him staying).
"Sami has a really good mentality. He is always ready and good with his teammates when he is not playing.
"I am not just saying these things because I have to. They are true."