With surgery not deemed necessary, the Scotsman has been undergoing intensive physiotherapy sessions to improve the healing process, but has run out of time for the fractures to 'weld' back together.

The Sterilgarda Husqvarna Max rider, who finished fifth in the Qatar season-opener, is now setting his sights on a return to the world championship at the following COTA round, which takes place just a week later from April 8-10.

“I've worked every day with my physiotherapist, with the aim of returning for the Argentine Grand Prix," McPhee said. "Unfortunately, after a thorough examination, the doctors informed me that the fracture needs more time, before it can be 'welded'.

"We return to work with the intention of recovering for the grand prix that will take place in Texas the following weekend. I’m very sorry I can’t race in Argentina, because I really love that track. I can’t wait to get back to Texas.”

McPhee's team-mate Ayumu Sasaki will need to serve a long lap penalty at Termas de Rio Hondo for a late tangle with Qatar winner Andrea Migno in Sunday's Mandalika race.

Migno's DNF means that Indonesian race winner Dennis Foggia now heads the early Moto3 points standings.