Sam Allardyce admits he will not risk injured Blackburn strike pair Jason Roberts and Roque Santa Cruz unless they are 100 per cent fit.Rovers have struggled for numbers in attack in recent weeks with centre-half Christopher Samba even asked to fill in at Liverpool.But despite Saturday's 1-0 defeat at fellow strugglers Stoke leaving them just three points above the Premier League drop zone, Allardyce refuses to risk the pair.Santa Cruz has been the biggest blow to the club having endured an injury plagued second season in England with his latest knee problem keeping him sidelined for well over a month."I think Jason will be closer than Roque but we have to be certain that they are 100 per cent fit," Allardyce told The Sun."We have thrown away far too many valuable points. But this is the only time we have been defeated by a team around us in my time in charge."All the defeats have come from the top-five boys."We need a no-lose mentality. Yes, we would like to win the game but we have to make sure we are not on the wrong end of a defeat."