Dejected Craig Mackail-Smith has labelled the departure of Albion’s injured skipper as “a massive turning point” in their play-off defeat.
But the striker conceded the Seagulls were not good enough to reach Wembley.
Gordon Greer left the 4-1 semi-final defeat at Derby yesterday with a hamstring problem.
His defensive sidekick Matt Upson had already been ruled out of Albion’s biggest game of the season.
Mackail-Smith said: “Losing GG was a massive turning point. He’s the leader at the back.
“He keeps the tempo going, he keeps the boys calm.
“For him to go off was really difficult and to lose Matty as well for such an important game was a blow.
“He (Greer) had been warming up well, he trained well. There didn’t seem to be any problems.
“The pitch was quite wet and slippery so I don’t know whether he did it during the game.
“But he was a big loss to us and a big part of why we struggled during the game.”
Mackail-Smith, who came off the bench, praised Derby’s efforts to settle the tie on home turf.
He said: “They were fantastic over the two games and over the season.
“They go forward with pace, they pass the ball forward, they don’t ever seem to turn back and play back.
“They just want to go forward with pace, they go forward with pace and they gave us a good hiding.”