They are almost out of ear-shot as it is, with Jamie Ness and Rhys McCabe both stagnating in English football.
The midfielders matured through the youth ranks at Rangers but became part of the exodus from the club in the summer of 2012 after the club went into administration. Ness chose to pack his bags for Stoke City and McCabe also made for Sheffield Wednesday.
However, far from thriving in their new environment they are now experiencing the football equivalent of Siberia; Ness has appeared in just one match for Stoke, as a substitute in a Capital One Cup tie against Swindon Town last year, while McCabe has had just two minutes of first-team action for Wednesday in the past four months.
Sinclair is sure that both of those players' careers would likely have been better served by staying at Ibrox. "I'm fairly certain that if Ness and McCabe had stayed they would be in the first team and staying there," said Sinclair. "I had faith in these young players and I can't hide that I'm still disappointed by their actions. Maybe these kids will look back and feel they made the wrong decision - but maybe not. I don't know because I don't converse with them anymore."
In contrast, Macleod has flourished in the Rangers team this season and has held on to his place despite the arrival of more experienced players. Of course, circumstances had forced Ally McCoist to dip into the academy a year ago and expedite nine players into his first team. However, it is a source of pride to Sinclair and his staff that Macleod is thriving, while Andy Little, Fraser Aird and Robbie Crawford are also key members of the squad. The coach is confident that there are more on the way.
"We think that we are doing a good job but often it is not accepted that we are," he said. "I don't think administration has made Rangers any less attractive to young players. You could say there has never been a better time to be a young player at Rangers."