David Artell wants Grimsby to be even more ruthless despite beating Shrewsbury 3-1 at home to reach the Carabao Cup second round.
The Mariners have scored nine goals in their first three games of the campaign, with Justin Amaluzor, Cam Gardner and Jaze Kabia on the scoresheet this time.
Grimsby were dominant for large spells and Artell said: “I thought we were better than them all over the pitch. The only issue I had was that we didn’t assert our dominance earlier in the game.
“We want to become even more ruthless with the big chances we have, but also in our own box defensively.
“They never should have scored in this game on the balance of play, and I know it was unlucky in terms of the kind of finish, which Christy [Pym] couldn’t do anything about.
“We want to become super ruthless, almost brutal with our play, because we haven’t done too badly so far with nine goals in three games.
“We can be even better, because that game should have been put to bed after 40 or 60 minutes.”
Shrewsbury had the consolation of scoring their first goal of the season through Tom Sang’s looping effort.
Manager Michael Appleton said: “I thought in the first half we were a little bit nervous and tentative, perhaps a hangover from the weekend. We did improve in the second half.
“We were against a good side who have started the season really well, so for us to show some spirit and look like we could get back in the game was good.
“It’s a shame in some sense because I felt we were hard done by with a couple of big decisions.”
