I think the best thing you can say about Annunen last night is that there is NHL potential there. He's got a good base of skills, especially on the mental side, that will give him a chance at being a regular NHLer. I do like his ability to quickly react to shots and just his tracking in general. When watching him you never really worry about him losing the puck even through traffic so he's always going to be giving himself a chance to stop the puck. However he really, really needs to work on his behind-the-net play. He just always believes the puck carrier is going to continue going forward and not do a reverse pass. It didn't burn him in Ottawa (almost did), burned him last night though. Annunen needs to find a better way to track the puck behind the net because it won't take long for video coaches to point it out for pre-scouting.
One of the biggest aspect Annunen is going to have to work on in the off-season is essentially going from a 4-speed car with the acceleration of a 2014 Elantra to a 5-speed car with the acceleration of something with a V8 at least. Annunen has essentially spent his whole hockey life playing the exact same way with minor adjustments and linear-ish improvements. Movement wise he's good enough to keep up with the AHL as they don't have the execution or consistent high end pace/speed we see in the NHL. What we've seen in the NHL so far is that when the pace/speed picks up Annunen is still just plodding along. It's like if he's in a cross country race and he's keeping up with the majority of the group but for the last 500M the top runners start to sprint but Annunen doesn't break his pace. He doesn't slow down but he can't speed up. Even when you're 6' 4" there's still a good amount of net to shoot at and with how fast a lot of these players can get their shots off you don't always have time to react. You just need to get proper positioning and challenging.
The one good thing about Annunen being with the Avs is that so far Parkkila has shown he likes to have his goalies get aggressive when the situation calls for it. I believe JoJo mentioned that last season in that Parkkila wanted him to be more aggressive in his challenging because it's just so hard to stop shots where they are at the limits of human reaction time. And some goalies just aren't going to have high levels of reaction speed so you have to find ways to cover for that. Getting aggressive though means you need to get there quickly and have your feet set immediately. It's very, very difficult to react while you're moving. That's pretty much the general/overview of what Annunen will need to improve on.