Despite Toronto's strong start to the campaign, Nelson believes that his side are still a long way behind some of their domestic rivals because of the large number of personnel changes that they made in pre-season.
"I don't think we're a top team right now," he told reporters.
"We're very well-organised, but I don't think we've seen the best of us. And you won't see the best of us because we're still new.
"I think we still have a long way to go as a team. We'll play better than that probably and lose games."
Six of the players who started Toronto's win over United were not at the club last season.