Reds Manager Danny Wilson spoke to Barnsley Player following his side's 2-1 defeat at Chesterfield.
"We've lost the game with a couple of incidents in our defensive area," said Wilson.
"That was the major problem. Two long balls down the middle of us has cost us twice, other than that I feel we played quite well.
"The two isolated incidents have costed us the game. The second goal, in particular, was a killer one because at that moment we were getting back into the game.
"We can't really complain because we've had a lot of chances. Unfortunately we didn't take our chances like we have done in recent games."
Keith Treacy gave Barnsley a lifeline in the 85th minute but the damage had been done by a brace from Eoin Doyle.
"I thought it was a good game," continued Wilson. "It's never the best when you don't win, obviously, but it was a good game and I thought both teams gave it a good go.
"The first 25 minutes or so, Chesterfield got us on the back foot and I thought (Gary) Roberts was outstanding during that period.
"We wrestled back into the game and we started the second half really well but then we conceded."