Orr made the journey to Woburn, Milton Keynes, England but skipped the pro-am. Englands Sam Walker will replace him.
With Orr out of the picture, Michael Campbell is the favorite to take home the title on The Marquess Course.
The Kiwi is ranked second on the Order of Merit and finished tied for fourth in last weeks Volvo PGA Championship, which was won by Andrew Oldcorn.
Oldcorn is also in this weeks field; as are Lee Westwood, Colin Montgomerie, Ian Woosnam, Darren Clarke, Thomas Bjorn and 2001 European Ryder Cup captain Sam Torrance.
Montgomerie is coming off a disappointing tie for 17th at the Wentworth Club, where he had won the three previous years.
Montgomerie, who won the Order of Merit from 1993-99, is currently 33rd on the money list. He is 10th in Ryder Cup standings.
Last year, Orr fired a 10-under-par 62 in the second round to take command of the tournament. He shot 68-70 over the weekend to beat Per-Ulrik Johansson by two shots. It was Orrs second victory of the season. He also captured the Algarve Portuguese Open.
Full field and tee times from the British Masters