"He (McPake) has two small fractures at the bottom of his back and it is looking like it'll be for months now and not weeks as we initially thought," Boothroyd announced at the weekly press conference to Sky Blue Player.
"It's unlucky that this injury has hit James and we must look to get him back as soon as we can.
"He's currently in consultation with a surgeon and it's only once we speak to James along with the physios that we'll have a definitive timetable for his return.
"But I do believe that there is an operation on the way.
Speaking about whay may have lead to McPake getting this injury, Boothroyd said: "You have got to play hurt sometimes, as no-one plays at a 100% now, but unfortunately for us James has probably trained too hurt because he's the sort where we actually need to coax him to calm down a bit.
"But James is so desperate to play and win and this injury is probably just a culmination of factors.
"Ben (Turner) is still dealing with his injury and is getting closer to a return and then we have Richard (Wood) and Martin (Crainie) who have filled in for us at left-back with the problems we've had there and are more than adept and keen to play the more central role.
"So we still have 3 or 4 players waiting to fill the void left by James' injury."
"But I do believe that there is an operation on the way.
Speaking about whay may have lead to McPake getting this injury, Boothroyd said: "You have got to play hurt sometimes, as no-one plays at a 100% now, but unfortunately for us James has probably trained too hurt because he's the sort where we actually need to coax him to calm down a bit.
"But James is so desperate to play and win and this injury is probably just a culmination of factors.
"Ben (Turner) is still dealing with his injury and is getting closer to a return and then we have Richard (Wood) and Martin (Crainie) who have filled in for us at left-back with the problems we've had there and are more than adept and keen to play the more central role.
"So we still have 3 or 4 players waiting to fill the void left by James' injury."