Gordon D'Arcy has condemned England's use of Sam Burgess after Saturday's loss to Wales left them on the brink in the World Cup.
The former Ireland centre believes Burgess is still far too inexperienced to be successful at Test level, and felt his lack of understanding of the centre position cost England dear.
Stuart Lancaster's team went down 25-22 at Twickenham, and now have to beat Australia on Saturday to have any chance of reaching the last eight.
And for D'Arcy, one half of Ireland's record-breaking centre partnership with Brian O'Driscoll, Burgess is currently not up to the job.
"Burgess lacks the sense of timing, in attack and defence, required to be effective at international level," D'Arcy wrote for the Irish Times.
"His naivety embarrassed those around him and severely damaged England’s chances of reaching the quarter-finals.
"Stuart Lancaster picked a league convert who doesn’t know how to play inside centre for the biggest match England have played since the 2007 World Cup final. To compound the problem, Brad Barritt was out of position at 13 and exposed accordingly when it mattered most.
"I think, for now, Burgess can only be effective alongside Bath team-mate George Ford as they have developed some form of understanding before George’s dad, Mike, shifted Burgess into the back row.
"By picking Owen Farrell, Burgess and Barritt, England didn’t come to Twickenham to play rugby. We all knew this.
"Burgess never got to the pace against Wales. He clearly bust a gut but effort and strength were never going to be enough. Barritt was arguably worse and badly exposed for the Gareth Davies try.
"By then the Burgess experiment had been abandoned because the England coaching team accepted, long after everyone else, that he had no idea what was happening around him."