The former Australia cricket coach John Buchanan says batsman Kevin Pietersen could be a significant liability for England if he doesn't pile on the runs in the upcoming Ashes series.
Buchanan says Pietersen is a quality player, but if he's not scoring runs for the English, he could become a major problem for the team.
He says two of the things that will be tested in Australia are strength and unity, and Pieterson is yet to understand his role within the team.
But Buchanan says England possess the mental strength that's been missing from previous sides, and could be world leaders in cricket within the next few years.
