Lucho Gonzalez believes it is a good time for Porto to be playing Manchester United in the UEFA Champions League.
Manchester United's march towards the Premier League title has faltered in recent weeks following a heavy defeat at home to Liverpool and a surprise loss against Fulham.
They returned to winning ways with a dramatic 3-2 success against Aston Villa on Sunday but Lucho believes they could still be vulnerable.
The 28-year-old playmaker believes Porto can take advantage and spring a major surprise in the first leg of their quarter-final at Old Trafford on tonight.
