Manchester United came into the last 32 tie on the back of some mixed form and Real Sociedad were expected to put up a stiff fight in the European tie.
But the Red Devils blew away Sociedad in the first leg in Turin and have more or less booked their place in the last 16 of the Europa League ahead of the second leg at Old Trafford next week.
Chadwick feels Manchester United have drawn a line in the sand with the win over Sociedad and made a statement to the rest of the teams in the competition with the result.
He believes that barring the Premier League sides left in the competition, none of the team will fancy facing Manchester United in the Europa League.
Chadwick said on MUTV: “It’s a real marker that has been set now for this tournament.
“4-0 up, looks like in the next round and bring on whoever comes.
“If you beat Sociedad, one of the better teams in the tournament, it is a massive statement and everyone will fear them.
“The teams that aren’t fearing the draw are the other English clubs because the other teams, United can go there and have shown tonight that they can get a very good result.”
Manchester United are likely to rest a few players for the second leg next week ahead of their big league clash against Chelsea.