The Newport Gwent Dragons scrum-half suffered an ankle injury playing for a northern hemisphere select side in last Saturdays IRB Tsunami Aid match.

The 25-year-old, who looked set to continue on the Wales replacements bench as cover for Dwayne Peel, could also be unavailable for a possible Grand Slam decider against Ireland in Cardiff next week.

Gareth suffered a rotational strain to his right ankle, said Wales team physiotherapist Mark Davies.

And we now know the injury is sufficiently serious to rule him out of contention this weekend and possibly the week after.

We will have a better idea of the extent of the problem when the results of a scan which Gareth had (on Tuesday) afternoon come through.

Mike Phillips, Peels Llanelli Scarlets colleague, is now likely to take Coopers bench spot when Wales coach Mike Ruddock announces the side for Edinburgh on Wednesday afternoon.

Phillips, a former Wales Under-21 Grand Slam skipper, made his Test debut against Romania just before the 2003 World Cup.

Wales go into the clash at Murrayfield as firm favourites after winning their first three RBS 6 Nations matches this year.