Indeed, with Ajax's rich history - four times European Cup winners, 30 times Dutch champions - the manager says it would be foolish to do so.
"I worry more about Ajax's history than any individual in their team at this moment in time," Sir Alex said. "I respect that history. It's fantastic that Ajax have retained that philosophy for so many years. They play the same style, the stame system, the same tactics. It's fantastic and I respect that.
"The standard of Dutch sides is always good. Unfortunately the problem is that all the best players want to leave and go on to bigger things, but Holland keeps producing players and it's a great credit to them."
The Reds have already been surprised by less-fancied opponents in Europe this season, with Switzerland's FC Basel earning a 3-3 draw at Old Trafford before beating United on matchday 6, a result that effectively dumped Sir Alex's men out of the Champions League.
"We've taken that lesson from [the defeat in Basel]," the boss acknowledged. "We threw away tthe game against Basel at home [United were 2-0 up at half-time] and were unlucky against Benfica in another home game. That caught us short and we suffered for it.
"But I feel good about being in the Europa League. It's a tournament we're going to try and win and we have a responsibility to do better than we've done earlier in the season. Going out of the Champions League wasn't expected, but it happens.