LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain reacts during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

Spain's Fernando Verdasco serves a ball to Argentina's Juan Martin Del Potro during their ATP World Tour Finals tennis match at the O2 Arena in London, Tuesday Nov. 24, 2009.

Spain's Fernando Verdasco returns a ball to Argentina's Juan Martin Del Potro during their ATP World Tour Finals tennis match at the O2 Arena in London, Tuesday Nov. 24, 2009.

Spain's Fernando Verdasco reacts during his ATP World Tour Finals tennis match against Argentina's Juan Martin Del Potro at the O2 Arena in London, Tuesday Nov. 24, 2009.

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Spain's Fernando Verdasco checks his foot during his ATP World Tour Finals tennis match against Argentina's Juan Martin del Potro at the 02 Arena in London, Tuesday, Nov.24, 2009. Verdasco lost the match.

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/CARL DE SOUZA (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

Spain's Fernando Verdasco reacts during his ATP World Tour Finals tennis match against Argentina's Juan Martin del Potro at the 02 Arena in London, Tuesday, Nov. 24, 2009. Verdasco lost the match.

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Spain's Fernando Verdasco returns the ball to Argentina's Juan Martin del Potro during their ATP World Tour Finals tennis match at the 02 Arena in London, Tuesday, Nov. 24, 2009.

Spain's Fernando Verdasco returns the ball to Argentina's Juan Martin del Potro during their ATP World Tour Finals tennis match at the 02 Arena in London, Tuesday, Nov.24, 2009.

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/CARL DE SOUZA (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

Fernando Verdasco of Spain plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Fernando Verdasco of Spain gestures as he plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

Fernando Verdasco of Spain serves against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/GLYN KIRK (Photo credit should read GLYN KIRK/AFP/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain reacts during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

Fernando Verdasco of Spain plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/CARL DE SOUZA (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

Fernando Verdasco of Spain plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/CARL DE SOUZA (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain serves the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Clive Brunskill/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Clive Brunskill/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Clive Brunskill/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Clive Brunskill/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain celebrates a point the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain returns the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)

Fernando Verdasco of Spain plays against Juan Martin Del Potro of Argentina in a Singles match during the Barclays ATP World Tour Tennis Finals in London, on November 24, 2009. AFP PHOTO/CARL DE SOUZA (Photo credit should read CARL DE SOUZA/AFP/Getty Images)

LONDON, ENGLAND - NOVEMBER 24: Fernando Verdasco of Spain serves the ball during the men's singles second round match against Juan Martin Del Potro of Argentina during the Barclays ATP World Tour Finals at the O2 Arena on November 24, 2009 in London, England. (Photo by Julian Finney/Getty Images)