Shrewsbury manager Micky Mellon says his players "can do better", despite seeing them book an FA Cup third-round tie at Championship side Cardiff City.
Shrewsbury made hard work of National League side Grimsby, with Abu Ogogo scoring an injury-time winner.
Mellon told BBC Radio Shropshire: "You have to take the rough with the smooth and not get over excited, but keep a realism on everything.
"I know my players are better than they showed me tonight and they know that."
Grimsby had originally held Shrewsbury to a goalless draw in the second-round tie to set up Tuesday night's replay.
Ogogo scored in the second minute of added time to put Shrewsbury into the third round for the first time since 2011-12.
"We've got what we set out to do," continued Mellon. "Sometimes it is just about getting that result and getting into the third round.
"I am sure the chairman will be happy with a few more quid and everyone is over the moon."