Andy Murray is told he must play in the ATP World Tour finals

Andy Murray has been told he must play in the ATP World Tour finals after hinting he may miss the event to prepare for the Davis Cup final.

Great Britain are into the competition decider for the first time in 37 years and will attempt to follow up their last win in the event in 1936 with another against Belgium in November.

The Belgians have a fortnight to declare what surface they will host the tie on and are thought to favour clay as it is the one Murray is least comfortable on.

He suggested after Sunday's win over Australia in Glasgow he could miss the ATP finals at the O2 in London to spend time preparing on clay given the Davis Cup clash a week later.

In doing so, he would potentially make a large financial sacrifice given the tournament in London gives more than £1.2m to an undefeated champion.

But Murray has been told his participation there - on a hard court surface - is compulsory and that means he faces a hectic end to the season with limited preparation for the Davis Cup.

The Scot is currently managing a back injury and believes he needs more time working on clay and adapting to it than playing at the O2 will allow.

ATP president Chris Kermode - a long-time ally of Murray's - has made it clear he expects the 28-year-old to play in the capital.

He said: "The Barclays ATP World Tour Finals is a mandatory event on the ATP World Tour and all players who qualify, unless injured, are required to compete in the event.

"He [Murray] has had a fantastic season and earned his place among the world's top eight players to compete at the season finale.

"We are aware of the comments made after the Davis Cup tie in Glasgow. However our expectations are that, if fully fit, Andy would compete in this year's tournament.

"Unless we hear otherwise via an official withdrawal, he is still entered to compete at the O2."