Spanish MotoGP rider Sete Gibernau may have to miss this weekend's race in Portugal after a collision on the final corner at Jerez aggravated an old shoulder injury.

Spanish MotoGP rider Sete Gibernau may have to miss this weekend's race in Portugal after a collision on the final corner at Jerez aggravated an old shoulder injury.

The explosive rivals exchanged the lead several times on the final lap of the first race of the season at Jerez on Sunday, before the final corner, when it all changed. Both Gibernau's Honda and Rossi's Yamaha dived into the inside of the final corner, before making contact in a move that Rossi admitted was "hard".

The Spaniard ran wide through the gravel pit, and claimed second spot while the Italian racer finished first.

"It was a hard battle with Gibernau, he was very fast today and rode very well," Rossi said. "I got in front with two laps to go but unfortunately I made a big mistake in the middle of the last lap on the braking and Gibernau got past. We passed each other again and touched two or three times before I passed him at the last corner. It was a hard move and I'm sure Sete is angry, but this is racing."

The tight-lipped Gibernau flew to Barcelona immediately after the presentation to have his left shoulder - which came into contact with Rossi's handlebar - examined. According to the official medical report, the Spaniard had "acquired a lesion to the rotator cuff of his left shoulder and to the tendon which will require rest and treatment."

The Honda rider had previously undergone two surgeries to the troublesome shoulder and has begun a course of physiotherapy to regain the full use of his shoulder before the next race this weekend.

However, the medical report has indicated that Gibernau's inclusion in the starting line-up at Estoril is still in doubt, an announcement that would come as a shock to his scores of loyal supporters.