The Black Cats travel to Stamford Bridge this weekend in a relegation battle nobody foresaw.
Jose Mourinho’s side have endured a slump of epic proportions this season, sitting just a point above the bottom three after 16 games.
They have already suffered nine defeats this season, with Monday seeing them beaten by surprise leaders Leicester City.
The game at Stamford Bridge has suddenly taken on the air of a relegation six pointer then, with the Black Cats finding themselves 19th in the table but just three points behind Chelsea in 15th.
And while they would be confident of beating the Blues given their form, Fletcher has warned them not to underestimate what is still a world-class team.
“It will be a very different game due to the situation both teams are in,” he told safc.com.
“Because of previous years we’re used to this situation but it’s a whole different ball game for them and they aren’t used it.
“We can’t go there and underestimate them because they’re still Chelsea and they still have the same players they did last year, so they’re a world-class team.”
Given the way both sides are performing of late, it is easy to imagine that Sunderland will be confident of securing a much needed win this weekend.
They are looking more of a unit under new manager Sam Allardyce, something Jose Mourinho’s side are not, with them looking like a team of individuals and it showing in their displays.
In a season of so many upsets Sunderland will surely fancy adding another to the list on Saturday afternoon.