Rafa Nadal has confirmed he will miss the next six to eight weeks with the hip flexor injury he sustained at the Australian Open."Today I was at the Teknon Tennis Clinic in Barcelona where they tested me," wrote Nadal Thursday on Twitter."They confirmed the results from Melbourne and the recovery stages are still the same."Initial scans showed the 22-time Grand Slam champion had a moderate muscle tear which did not require surgery."The treatments needed have been established and in three weeks they will carry out new tests to see how it is evolving," added the 36-year-old Spaniard.The reigning Australian Open champion was eliminated by US player Mackenzie McDonald 6-4, 6-4, 7-5 in the second round last week during which he suffered the injury.The projected timeline puts his participation at the ATP 1000 Indian Wells and Miami events in March in doubt, which would see him plunge down the rankings.Nadal will more likely target being ready for the clay-court season in mid-April, leading into the French Open in May, where he will be chasing a 15th Roland Garros title.