That has occurred at such a rate that the Hearts manager might be commended for simply keeping up; Ryan Stevenson, Jason Holt, Gary Oliver and Mark Ridgers among those whose injuries have exacerbated a shallow squad. Scott Robinson would also miss out at the weekend as the Tynecastle side lost to Celtic.
When Locke names just four outfield players as substitutes against Kilmarnock on Boxing Day, it will be a cry for help but one the manager knows will not be answered. There were a few empty seats in the dugout at Parkhead too, since Locke would refuse to draw two more callow young players into his first team from the youth system - instead leading them off the bus and having them seated in the stand.
There is a necessity for the brightest members of Hearts' youth teams to grow up fast but Locke has become wary of the cost. He would describe the latest two players to be graduated as being "just out of school" and the Hearts manager was not convinced either would learn anything from closer involvement in an uncomfortable defeat by Celtic.
The situation is unlikely to have improved by the time the team return to Tynecastle on Thursday and Locke is expected to select an incomplete bench once more. "I brought a couple of young lads with the squad but they had just left school in July," said the Hearts manager. "It would be wrong of me as a manager to put them on the bench. We are a club renowned for developing players but I had two lads in the squad on Saturday who just left school in July.
"They are doing okay for the under-20s but are miles away from the first team. If I was to throw them on at Parkhead against the likes of [Kris] Commons and [Georgios] Samaras, I don't think I'd be doing them any favours. It's a situation we are in and we have no one else to blame but ourselves. But I also have to protect these young players.
"The injury situation hasn't changed. Unless some of them are like Lazarus in the next couple of days then we'll probably only be able to again name four outfield subs on Thursday."
Kilmarnock would deliver a show of strength at the weekend with a win over Partick Thistle which has taken them 18 points clear of Hearts. Locke is aware that his club must begin to make up ground over the festive period of the campaign will likely be lost early in the new year. "I am hopeful that we can get through this period and pick up a few points," added the Hearts manager.