With this level of personal familiarity with the team captain and some time spent under the head coach in Junior, it's a good bet that Dermott will make the team after his tryout and play some NHL games.
Dermott is only 27 years old and was drafted in the second round by the Toronto Maple Leafs. He's gone on to play 329 career NHL games with the Leafs, Vancouver Canucks, and Arizona Coyotes. He's a smooth-skating defender who can play a two way game, but is prone to errant passes or some defensive coverage mistakes. However, there's undoubtedly talent there, and the Oilers clearly believe in him with the tryout contract.