The Irishman could be out until April after his ongoing problem began to impinge on his movement, forcing him to book in for an operation this week.
The blow will leave Houston with just David Goodwillie and the inexperienced Johnny Russell and Andis Shala up front following the departure of Danny Cadamarteri hours before the closure of the transfer window.
He said: "I might be trying to bring someone in who is out of contract but we've got good young strikers.
"Andis Shala has been desperate for a chance, Johnny Russell has been doing exceptionally well and he is a striker, I have always said that.
"So we have a couple underneath and as I say, without naming names, I might bring someone else in to have a look at. If he is any good, we might take him on until the end of the season."
Source: PA
Source: PA