He was due to play against world champions South Africa last Saturday, but withdrew from the Wales line-up less than 24 hours before kick-off.

Ospreys star Henson, 26, was not considered for this Friday night’s meeting with Canada, and he will now also miss Tests against New Zealand on Saturday week and Australia seven days later.

Henson is expected to be sidelined for a month while he undergoes what the Welsh Rugby Union has termed “a period of rehabilitation on his problematic Achilles”.

Henson’s ankle was scanned yesterday and he had an injection from specialists to help alleviate the injury.

He has been troubled by the Achilles problem for several months, and last played for Wales in their Six Nations title-clinching victory over France in March.

Henson suffered a serious ankle injury while on Ospreys’ Heineken Cup duty in April - in addition to the continuing Achilles complaint - and he has only started three games this season.

“Consultations with UK specialists yesterday led us to conclude that an injection, followed by a specific rehabilitation protocol which will take place over the next few weeks, was the best way forward,” said Wales team physiotherapist Mark Davies.

“Gavin has now had his injection and will be out of action for approximately one month.

“He has been given an injury-specific training programme to follow in that time, which should provide a resolution to his problem.”

After the autumn series, Wales are next in action on February 8 when they launch their RBS 6 Nations title defence against Scotland at Murrayfield.

At this stage though, it is far from clear whether or not Henson might require surgery, which could threaten his whole season and possibly participation on next summer’s Lions tour to South Africa.