Karl Robinson expects Truro City to park the bus against Charlton on Sunday.
The National League South side are the first Cornish club to make it to the first-round proper of the FA Cup since 1969.
And the Addicks will be huge favourites going into the game at the Valley.
Charlton manager Robinson told News Shopper: “Listen, in the games we've seen so far, with all due respect, can you see them coming out at us? I guarantee you they won’t.
“So we have to work on playing against a low block. The fans will be behind the goal, and the players will make it difficult for us.
“They’ll probably look [to score from] a set-piece or breakaway. They’ll be working hard to deny us space and we’ll work very hard on ball speed and making sure we’re dominant.”
The FA Cup is well known for pulling off massive upsets.
Last season’s competition saw fifth tier minnows Lincoln City knock out Brighton and Ipswich, while non-leaguers Sutton United beat AFC Wimbledon.
And Robinson insists respect will be shown to Truro City to avoid a shock defeat.
He said: “We won’t lose focus, we’re going to play a very strong team on Sunday. We’ll take it very seriously.
“We want our players to have minutes as the Shrewsbury game has been called off.
“Truro’s players will be honest and hard working. They’ll have some talented players amongst them.
“They’ve done unbelievable to get to this round. They won’t want to stop at Charlton, they'll want to go further. We've got to make sure we’re not that team.”
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