Mark Warburton was left rueing two soft goals as Nottingham Forest left Hillsborough pointless after defeat against Sheffield Wednesday.
Ben Osborn had brought Forest level in the first half but Warburton was left frustrated with Steven Fletcher's goal just after the hour mark which proved crucial in the way the game panned out.
He said: "I thought they came out very quickly from the first whistle. We had to change it quite early on in terms of shape then the change after half an hour was purely tactical to bring Andreas on.
"We gave away a soft first goal, we gifted it to them, but we responded and rallied well and got the deserved equaliser and at half time we thought we were in a decent shape.
"We then came out and for the first 10 or 15 minutes we were on top, we were controlling the tempo of the game and it was pleasing. The substitutions were to then try and maximise that but we then gifted the second goal.
"It was a free header inside the six-yard box and goals change games. In that split second the complexion of the game changes and they were tough to break down.
"It was disappointing that we can come to a tough venue, play well and yet that one goal changes everything.
"There was no lack of work ethic, no lack of desire but we have gifted them two goals and you can't expect to walk away with the points if that happens."