Newcastle assistant Iain Dowie said that although it was unfortunate, there was no ill-feeling from Shearer towards Martins.
"There hasn't been a falling out with Obafemi Martins and the matter has been dealt with," Dowie told the club's official website.
"It's gone and it's in the past and he has said he is fully behind the cause here.
"We never said there wasn't an injury. All Alan expressed was his disappointment that he had not been told about the injury until 11.15 on Saturday morning, which was too late.
"It was disappointing, that's all, because we had been working on a system all week and then had to scrap it at the last minute because of the injury to Oba.
"There is no bad feeling. He has gone away for a scan and hopefully the prognosis will be a good one and he will be back involved quickly because he is an important player for us, no doubt.
"The communication should have been better but, to be fair to Oba, he was desperate to be involved and maybe that was why he kept quiet about the injury."