He’s said that despite his protracted contract negotiations with Carlton, he had never considered leaving.
"For me it was always just a matter of when the deal got done, not who it was going to be with. It's nice to get that behind me and look forward to pre-season now," Casboult said.
"Carlton had a lot of contracts to get done and mine just took a bit of time – that was all there was to that.
"Carlton is a great environment to learn in, there a lot of senior players around who are good old heads to learn from: 'Juddy' (Chris Judd), 'Murph' (Marc Murphy) and, on the forward line, Jarrad Waite and Lachie Henderson.
"I'm really happy to be able to stay on for another couple of years."
Casboult is also confident he has only begun to scratch the surface of his potential.
"I guess the sky's the limit really," Casboult said.
"I'm still 24, have only played 30-odd games, so I like to think that with every game I'm just going to keep getting better and hopefully help Carlton get to that premiership that we're looking for.”
