Injury to Kieffer Moore rubs salt into wounds for Wigan Athletic manager
Latics crashed to a fourth damaging defeat on the spin, with Britt Assombalonga grabbing the only goal for a Middlesbrough side who were winless heading into the game.
Despite Latics now having gone 375 minutes without a goal, Cook reckoned the result on Teesside was harsh in the extreme.
"We left Preston very, very flat and disappointed," reasoned Cook, whose side played the last 10 minutes a man light after Kieffer Moore was forced off injured, with all three substitutions having been made.
"Obviously the result here's disappointing, but I thought we did smashing in the game.
"We played well, we created chances, we limited Middlesbrough to very few chances.
"Even with 10 men at the end, we were still the team pushing.
"But unfortunately we couldn't just get that goal, and that happens sometimes in football.
"We've got a new set of players, and we've got to integrate these players as quickly as possible.
"Of course we know how important results are, and this is a very unforgiving league.
"But our lads were excellent tonight, and they went over to the fans at the end, and they were all stood up clapping them.
"As a manager, and a player, when your supporters clap you off at the end like that, I think that means you've done okay.
"While we're really disappointed to have come away with nothing, I think the level of performance was very good."
With forwards Joe Garner, Joe Gelhardt, Josh Windass and Anthony Pilkington already out injured, Cook is keeping his fingers crossed Moore's problem isn't as bad as first feared.
"Unfortunately it looks like Kieffer's got an injury now, and they are starting to mount up," the Latics boss added.
"He's got a calf problem...and it doesn't look good."