Boro boss Westley insists he does not see Wednesday night's second-round tie at Goodison Park as a ''big day'' for the League One club because he knows how badly such occasions can go.
Referring to his time as Farnborough Town manager, Westley recalled an FA Cup fourth-round fixture at Arsenal in February 2003.
''I don't know about a big day,'' he said.
''I can remember preparing for a big day at Arsenal some years ago. I took my Farnborough side there, we had a man sent off, we got absolutely battered and it didn't feel like a big day at all. It was a horrific experience.
''So I don't look at it as a big day, I look at it as the next game and to win any game you've got to prepare properly.
''You've got to get ready for these games by giving them the respect they deserve. You need to appreciate why those players are at that level and why those clubs are where they are. If we don't do that then we run a big risk.''
Another third-tier team travelling to face top flight opposition is Walsall.
The Saddlers visit Stoke looking to complete a Potteries double, having beaten Port Vale in round one.
It was at this stage of the competition last year that Dean Smith's side played a full-strength QPR team - then managed by current Stoke boss Mark Hughes - who made light of their poor Premier League form to win 3-0.
Walsall manager Smith said: ''It's Mark Hughes again. He put out a full-strength team against us in the cup last year and I expect the same again.
''We're really looking forward to it. We've worked really hard to get into this round and it will be a game where we can play with freedom and try to get the result.
''We'll go there with a bit of confidence because of what we've done this season already.''
Assistant manager David Kelly insists Nottingham Forest will not be taking their foot off the gas as they look to maintain their unbeaten start to the season against Millwall at the City Ground.
In fact Kelly has set his sights high in a competition that the Reds have won four times.
''Millwall are a good side and we don't do weakened sides at this club. We have good quality players who want to win every game,'' said Kelly.
''Everyone wants to go to Wembley, every supporter, and the staff and players are no different.''
Forest last lifted the trophy in 1990, with their last appearance in the final coming two years later.
Watford host Bournemouth, who have already been beaten 6-1 at Vicarage Road in the league this season.
The Hornets made nine changes against Bristol Rovers in round one and manager Gianfranco Zola will once again utilise his strong squad.
''I'm not sure if there will be so many (changes) again but there will be changes,'' said the Italian.
''The cup is important to us. It is a good competition and we want to go forward as a team.''