(CNN) -- Six Nations champions Wales must do without star center Gavin Henson when they begin their defense of the crown against Scotland at Murrayfield on Sunday.
Henson has been in fine form for the Ospreys this season ahead of the Six Nations.
The Ospreys man has not recovered from a calf injury he picked up in training earlier this week and coach Warren Gatland has decided not to risk him.
Henson, who has missed the last seven Tests played by Wales with a variety of injuries, will have his fitness assessed ahead of the crunch match at home to England in the Millennium Stadium next weekend.
Wales completed a grand-slam clinching win over France in the 2008 season, the last time injury-hit Henson played for them in a Test.
Coach Gatland was hopeful of pairing Henson and Cardiff Blues center Jamie Roberts for the first time, but the tight calf has put paid to that.
Tom Shanklin, dropped to make way for Henson, will now come in to partner Roberts with Andrew Bishop drafted in as a replacement.
Wales have only beaten the Scots in Edinburgh twice since 1985, while their last trip to Murrayfield two years ago saw them produce a sorry display in going down to a 21-9 defeat.
Losing Henson is a bad omen for Wales, who have not lost a Six Nations game he has started.