Ipswich meet Nottingham Forest in the fifth round tonight.
McKenna said, “I think this is that round where if you can go through - as a club, as a group of players, staff, supporters, everyone - people will start looking at you being maybe one game from Wembley and what might be possible.
“But at this stage, we’re still away from home against a team who are third in the Premier League and having a really strong season, so we can’t look too far ahead, we can only focus on this game and if we can manage to get through to the next round, then everyone can dream a little bit more.”
Ipswich and Forest are at the opposite ends of the table.
And McKenna said, “I think you can be in a different position in the Premier League where the cup can sometimes become your primary focus,.
“There are probably a couple of teams in the league who have got the cup competitions as maybe their primary focus for the end of the season.
“If you’re at our end of the table or Nottingham Forest’s end of the table, the reality is that that’s not the case.
“But that doesn’t mean that you don’t try and go through. To go to a cup quarter-final, semi-final, final, to win a cup, these are things that you dream about and everyone wants in their careers, whether you’re a player or a supporter or a staff member.
“We’re certainly not going to shy away from an opportunity like that and we’re going to give it our best.”