The 21-year-old striker, who came through the ranks at Coventry, played in four friendlies for Rovers and was offered a deal.
But Jeffers turned it down after the club would not pay for his accommodation.
"He turned down the offer which surprised me," Moore told the club's official website. "We gave him the opportunity and I think he had half a chance.
"We haven't got loads of money to give him but he was looking for accommodation as well.
"I always thought that's what your money was for, I have to pay my mortgage out of my wages.
"You've got to be hungry in this game and for me he wasn't hungry enough."
Moore has also confirmed Inter Milan striker Bocar Djumo will arrive for his trial.
The boss added: "It's all gone quiet. We've chased the agent and I don't know what has gone wrong, it's certainly not on our part.
"We've done everything right, we've got permission from Inter Milan but I don't know what his agent is playing at."