Wednesday, one of just three Yorkshire representatives still remaining in the last 32 of the Cup, will be afforded the national spotlight at Stamford Bridge (6pm), with the fourth-round being screened live by the BBC.
Watching events from afar is likely to be recently-appointed manager Steve Bruce, who will officially take up his position on February 1 and be in the dugout for next Saturday’s Championship game at Ipswich Town.
The former Hull City, Sheffield United and Huddersfield Town chief is currently on a pre-planned family holiday in Barbados and has been in attendance at England’s opening Test with the West Indies.
But with the cricket likely to be over before tomorrow Bruce should get the chance to watch the Owls in televised action in just the sort of fixture that he would like to replicate on a regular basis through success in his new position at Hillsborough.
Looking ahead to tomorrow’s tie, with Wednesday backed by a big travelling contingent of just under 6,000 supporters, Agnew said: “Sheffield Wednesday is an amazing football club with a fantastic fanbase and they will be very vocal on Sunday evening.
“The game is live on BBC and gives the exposure that Sheffield Wednesday need and is just a reminder to the whole football world how big this club is.
“I do not think anybody involved in Sheffield Wednesday needs reminding because everybody realises how big the club is and the potential it has.
“But maybe it is a reminder to the rest of the football world that Sheffield Wednesday are playing in a huge game.
“Obviously we would like to be playing the likes of Chelsea every week.”
Acknowledging that Bruce, fully refreshed and recharged, is relishing his return to the frontline of management with Wednesday, Agnew added: “He is chomping at the bit and I am sure people will see in his press conference next week that Steve is excited and ready to take the challenge on.
“I can feel it in his voice that he is fresh, he is ready, he is prepared. He knows what is going on obviously with the contact we have had with him.
“He is a great guy and a terrific football manager. Once he comes in the building on a regular basis I think there will be a huge lift within, not just the players, but the staff around the training ground because he has the human touch with people.”
A positive performance and result at eight-time Cup winners Chelsea would increase the feelgood factor ahead of the arrival of Bruce and while the Owls are big outsiders ahead of their first visit to Chelsea since December 1999, Agnew is conscious of the Cup’s enduring reputation for surprises.
Almost four years to the day in the same round of the competition the former Middlesbrough No 2 helped inspire Boro to a famous 2-0 victory at Manchester City – on the same date as another Yorkshire side provided one of the biggest FA Cup shocks in modern times at Stamford Bridge.
That saw Bradford City stun Chelsea 4-2 and while a win for Wednesday at the same west London venue would not constitute quite as seismic a result, it would still reverberate across football circles.
On the task against Chelsea, who could hand a debut to new signing Gonzalo Higuain, Agnew – assistant to Bruce when Hull reached the FA Cup final in 2014 – added: “We will play on the front foot and be organised, while you always need a little bit of luck against the best teams in Europe.
“Cup upsets happen every year. Of course you need the bounce of the ball and a little bit of luck on the day. But the players have been terrific all week and there is an excitement around the training ground. There is a real buzz about the players and they are all looking forward to it.
“The one success we had with Hull was getting to an FA Cup final and playing Arsenal. We were underdogs that day and we were 2-0 up. We lost in extra-time, but we ran Arsenal very close.”
Owls loanee Michael Hector is ineligible to play under the terms of his loan from Chelsea.
Doncaster Rovers will be seeking to reach the fifth round of the Cup for the first time since 1955-56 this afternoon when they host Oldham Athletic, while Middlesbrough welcome Newport County – hometown club of Boro manager Tony Pulis.
Previews: Pages 3 and 4