The former Manchester United midfielder's current contract runs out at the end of next season but he said he considers hanging up his boots because of a hip problem.

"When I signed for Celtic I did say it would be best to maybe look at things in the summer," Keane said.

"They were keen for me to sign for the extra year, which I did. I will see how my hip is bearing up in the summer," he added.

The Irish midfielder revealed that he will examine how far the injury is affecting him before making any decision.

"I am due to go back to the hip specialist in the summer. It is important to be fair to myself and the club if it is affecting me," he said.

"I will weigh it up then but there are no guarantees about next season, I have to say," I added.

Keane, who joined Celtic in January after 12 years with Manchester United, had a problem with a hip injury since 2002; he said he wants to spend more time with his family.

"Since having the surgery in 2002 I have regarded every season as a bonus but I have got to look at the long-term side of it and see what is best for me and my family," he said.

"Over the last few months I have always put football first but, come the summer, I need to look at what is best for my family," he added.