Ashley Westwood and Chris Arthur, whose deals at Sixfields were set to expire shortly, have been told they don't feature in the new manager's plans.
"I made this decision now as I believe in being 100% honest with people," Boothroyd told the official club website.
"The two lads were not going to feature in the first team in the next few weeks. So I thought it was better to tell them now.
"They can spend Christmas with their families, and they are free agents for the January transfer window."
Saturday's goalscorer Bayo Akinfenwa meanwhile believes that Boothroyd has brought a new focus to the struggling Cobblers squad.
"The new manager and [assistant] Andy King have set out a game plan and they've been drilling that it into us," he told BBC Radio Northampton.
"The intensity of training has gone up 10 or 15%, the gaffer is meticulous in his details and I think we're going places - we'll put it right on the pitch."