The Red Devils required an injury time Marcus Rashford goal to beat Hull City, ensuring they head into the international break with three wins from their first three games.
On paper, United arguably have the strongest squad in the division, and Mourinho believes the team he has assembled have enough quality to claim the top flight title.
However, he is well aware that the Premier League is not like a number of other European leagues, with a host of teams strong enough to challenge at the top of the table for silverware.
Speaking to talkSPORT following United’s win over the Tigers, Mourinho said: “The squad can win the Premier League; the team can win the Premier League.
“But other teams and other squads can win the Premier League.
“For example, yesterday the German Bundesliga started, and you have already the feeling of who is going to win it.
“And in other countries, maybe two teams can win the title.
“Here, the first thing is who’s going to finish top four. That’s the first thing because the teams are so good.
“Today I watched Tottenham v Liverpool – these are two teams and squads who can be champions.
“So, it’s very open. But yes, we have the quality to be champions.”