The Northampton manager has again opted for a player he has worked with before with the non-contract signing of former Colchester United central defender Heath.
Formerly of Coventry City and Leicester City, Heath impressed in a midweek trial against the Foxes.
Boothroyd has also shown a willingness to take a gamble on attacking players in the past and has done so again with a one-year contract for ex-Hull City winger Emerton.
“I think he’s got a lot of ability and he just needs a place where he can show what he is all about," he told the official NTFC website.