Hinkley has enjoyed a superb trial period with the black, green and gold, starring in Gallagher Premiership games against Harlequins and Saracens.
There was a clamour among supporters for Saints to sign the 23-year-old for beyond the current season, and that is exactly what they have now done.
The highly-rated flanker began his career in Gloucester’s academy set-up in 2017 before moving to Exeter Chiefs three years later.
Hinkley found first-team opportunities limited at both clubs but produced several scintillating performances at age-group level for England – scoring a memorable try at cinch Stadium at Franklin’s Gardens for the Under-20s against Scotland.
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But having thrived in recent weeks after being unexpectedly thrust into Premiership action, incoming director of rugby Dowson is confident Hinkley has the tenacity to perform at the very highest level for Saints.
“Aaron’s been really impressive ever since he arrived here on a trial,” Dowson said.
“He’s a high-energy, aggressive player who is really good over the ball – as we’ve seen in the matches he’s played so far.
“One of his big points of difference is his speed, and the edge he brings when he plays.”
“We wanted to get him inside our environment on trial first to see what he’s about and how he could fit into our group, and he’s worked hard throughout his time with us.
“He was one of the standout performers in (head of Academy) Mark Hopley’s England Under-20s squad back in 2019. Hoppers has been so complimentary about the amount of effort Aaron puts into every session he’s involved in.
“It speaks volumes about his character that – after such a long time away from playing any competitive rugby – he was able to come into the side in a crucial Premiership match and play at an outstanding level, so we think the ceiling is high for him and we’re excited to sign him up on a long-term deal.”