Western Force captain Sharpe was last week ruled out of the seven-match tour of Japan and the United Kingdom with a shoulder injury.

Sharpe's withdrawal leaves a big gap in terms of Test experience and presence, with the UK sides tipped to give his team some torrid battles up front.

At 200cm, Sharpe is the same height as Horwill, but the other two locks in the squad Dean Mumm and Dave Dennis are 196cm and 192cm respectively.

Horwill and Mark Chisholm are likely to carry a heavier load than usual with Dennis uncapped and Mumm alternating between the second and back rows.

Injuries also wrecked the tour aspirations of ACT Brumbies star Peter Kimlin, the NSW Waratahs' Will Caldwell and the emerging Force duo of Sam Wykes and Tom Hockings.

Horwill, who missed last year's spring tour with a foot injury, emphasised it was not up to any individual to try and replace 79-Test veteran Sharpe.

''I think everyone needs to probably take more responsibility, especially with Sharpey missing out,'' Horwill said yesterday. ''We need to make sure that we take the responsibility on ourselves and don't leave it for someone else to do.''