The Northampton Town boss watched his team draw 1-1 with their fierce rivals, with Colin Larkin getting an equaliser late in the first half.

Two days previously Gray had said he had a fully-fit squad to choose from, and Akinfenwa was even made available for interview in the build-up to the game.

But the big striker was ruled out with a hip problem, and his manager admitted to a spot of psychological game-playing with his opposite number.

"I didn't want to show my hand to the opposition too much," he said. "He picked up a bit of a problem with his thigh in the game at Tranmere, and we actually tried to get him involved in training on Friday but it was too much for him and he had to stop.

"We couldn't risk him because we've got three tough away games coming up where we really will need him."

Peterborough went ahead in the game through a stinging George Boyd shot that flew past Chris Dunn's right hand.

There were some suggestions the rookie keeper should have kept it out, but Gray feels such a verdict is unfair.

"I've told Chris to evaluate what he does in every game," he said. "The most important thing is that he learns from everything he does. He's so keen to do well, we've given him the number one shirt and I am very confident in him. He made some good saves and I don't think he was to blame for the goal. It was a hell of a strike."

Meanwhile, Larkin has urged his team-mates to build on the derby draw at Stockport tomorrow night, saying: "We had a great result at Bolton but never really built on it.

"It's important we do that with this game and try to put a little unbeaten run together."