MILWAUKEE -- Angel Perdomo, just promoted from the alternate training site roster, trotted in from the bullpen to pitch the ninth inning of what would become a 6-3 Brewers win over the Cubs at American Family Field on Monday.

Moments later, he was walking to the dugout.

Perdomo’s season debut was delayed by a lineup card goof, with Brewers manager Craig Counsell taking the blame for what he described as a technological issue.

“Look, it's our mistake,” Counsell said. “It's an automated system now, that when you make a roster move, it's supposed to auto-populate the lineup [card]. But it's our responsibility to check the lineup. So for whatever reason it wasn't on the umpire lineup. It was on our other lineup card, but it wasn't on the one given to the umpires.”

The mistake may have had consequences for the Brewers, who quickly summoned right-hander Drew Rasmussen from the bullpen to close out a 6-1 lead in place of Perdomo, and quickly saw Rasmussen find trouble. A base hit, a walk, a wild pitch and a double gave the Cubs two runs and prompted a call to Josh Hader for the final two outs. Hader did the job, sealing the Brewers’ fifth victory in their last six games.

Counsell isn’t the only big league manager to fall victim to such a gaffe. Last August, Blue Jays reliever Jacob Waguespack was denied an outing in Atlanta because his name wasn’t on Toronto’s card. A month later, the same thing happened to the Yankees’ Tyler Webb when he was supposed to pitch against the Blue Jays.

Does that automated lineup card system need to be re-examined?

“It needs to be examined on our end, for sure,” Counsell said. “It's an easy fix for us. We weren't checking it because it was automated, and that's our fault, and that's on us. We were taught the lesson tonight that we've got to check it. And so that's how we'll approach it from now on, is to check every player.

“No question, it caught us by surprise. It wasn't a good feeling, that's for sure. But we got the ‘W,’ so we'll learn from it and set up a system and make sure it doesn't happen again.”