Hill praised the performance of his young half, who was up against World Cup winner Stephen Donald, and said: "I think that Joe has well and truly proved to people that he can play at this level,
"He had to prove a lot to everybody, quite naturally, including the coaches, the owners, the supporters and his fellow players.
"Through really sticking at it, after that disappointment at Gloucester when he could have crumbled, he has shown good mental resilience and played with real confidence.
"He looks very assured and he has shown that he is a genuine Premiership number ten.
"Joey and Andy Goode get on really well," he added. "We all know that Andy Goode is a good player and we needed to find out if Joe Carlisle could play at this level.
"It's important to have two number tens in a campaign like this. Andy has helped Joe a lot and they genuinely get on really well. I can now share the duties at ten between those two."