Raonic retires from semifinal match

The 20-year-old from Thornhill, Ont., retired 41 minutes into his semifinal contest against Spains Fernando Verdasco with a reported back aliment after dropping the first set 6-4. It came mere hours after Raonic advanced to his first-career clay court semifinal after defeating Frenchman Gilles Simon.

Source: http://www.cbc.ca/sports/moresports/story/2011/04/30/sp-atp-estoril.html?ref=rss