The Blues battled to a 2-0 thanks to goals from Pedro Neto and Enzo Fernandez.
"I’m pleased with the general performance, but I say that lightly, because we lost the game which is hugely disappointing," said Parker.
"We took the game to them in the first half, we showed a real intent - but the moments, when they came, we didn’t make the most of them.
"Those chances we created, if we’d taken one, maybe it’s a different game.
"Momentum can swing in football and that goal they got just before half time gave them a boost.
"We couldn’t quite get going at the start of the second half, we struggled to replicate the first half performance, but we dug in, played our way back into it, showing some real quality, only to be hit by a late second."
He added: "We just fell a bit short today, but if we perform like we did today for the remainder of this season, I feel we’ll be in a good place. I'm proud of my players.
"There was improvement from last time out against West Ham - and we will need to keep moving in a positive direction.
"This group will always give everything, that’s a great trait they’ve got. I’ll watch the game back tonight, we’ll reflect over the coming days and be ready for Brentford next weekend."