The young winger has been forced to fill in on the left hand side defence in recent weeks, due to Steve McClaren’s side’s lack of options at the back.
Newcastle opted against signing any defenders in January, and Lee feels that the fact that Aarons is having to play out of position sums up the problems that his former side are facing at the moment.
“We’ve got Rolando Aarons playing there at the moment," he said. "He’s just a young kid and that’s not his position.
“For a club the size of Newcastle, that’s ridiculous really.”
Aarons has been forced to play at left-back, as both Massadio Haidara and Paul Dummett are currently sidelined with injury.
The 20-year-old has tried his best out of position, but he was badly exposed during Newcastle’s most recent match against Chelsea.
The Blues beat McClaren’s team 5-1 last weekend, and Aarons was at fault for at least one of the goals that his side conceded.
Newcastle’s defensive vulnerabilities throughout the campaign have stopped them climbing up the Premier League table, and they are currently stuck in 18th place in the top flight table.