Mickelson needs to find a way to straighten up his driver to compete with the current big guns .
Mickelson 's performance against Henrik Stenson at the Open Championship last season Mickelson he still has vintage performances left inside .
Mickelson needs to find a way to straighten up his driver to compete with the current big guns but his performance against Henrik Stenson at the Open Championship last season shows he still has vintage performances left inside .