The Blues find themselves in the relegation zone after making a 10-game winless start to life back in the Premier League (D5 L5), while seventh-place Spurs are the division's leading scorers and boast an impressive record at home (W7 L1, F21 A5 all competitions).
Ange Postecoglu's side did, however, lose 3-2 at Galatasaray in a Europa League match last night and have the likes of Micky van der Ven, Richarlison, Timo Werner, Wilson Odobert and Mikey Moore sidelined through injuries.
Asked if this was as good a time any to go to the Tottenham Hotspur Stadium, McKenna replied: “It’s not a game anyone will expect us to go and get points from, but we believe that we can. That’s nothing to do with their injuries or schedule though.
"By my math, they’re probably only missing (Micky) van de Ven from their most common starting 11. We’re certainly going to have more important players missing this weekend (Axel Tuanzebe, Jacob Greaves and Kalvin Phillips). Yes, they had a game on Thursday, but they rotated the side and are well used to playing two games a week.
“But we have belief that if we play as a team and if we stick to the game plan we can get a result.
“We’re going to have to show energy, we’re going to have to be brave, we’re going to have to be super disciplined, to show organisation and resilience, we’re going to need all the margins to go in our favour in terms of set plays and game management and we’re probably going to need some luck. But all those things are possible on Sunday. We’ll certainly look to deliver as many of those that are under our control as possible.
“We know it’s a really tough game. This is probably the most physical game you could have anywhere right now because they are the most intense team in the most intense league in the world. They scored four goals against Aston Villa, four against Everton, four against West Ham, got three against Brentford and probably could have had double. They are a real attacking side and are pretty relentless with the way they go after goals. There is a lot to admire in that, but there is also, I believe, a way to get at any team. We’ll try and impose ourselves as well as we can and try and hurt them in as many ways as possible.
“It’s a great challenge. It’s one that I think, if we approach in the right manner, will make us stronger as a group."