Henman had spent most of the season in the top seven of the Champions Race, but slipped out in the final week of qualifying after losing in the third round of the Paris Masters.

The British number one played and won two singles and a doubles rubber for his country in their 3-2 win over Thailand even though he had struggled with a shoulder injury since August.

But the 27-year-old, who has refused the opportunity to be second reserve at the Shanghai event next week, says he may have returned to action too soon.

"The Davis Cup tie against Thailand was very important to me but came at a bad time and set me back a little bit," said Henman.

"Usually the indoor season is very good to me in terms of results, but this year I found it hard to compete while serving at three-quarter pace, which is understandable.

"While I've tried hard to be as positive as possible in pursuit of my goal to reach the Masters Cup, it's been very difficult to compete week-in week-out knowing I couldn't give my best due to the injury."