The calling card to Annunen's NHL play last year is that he just didn't give up many bad goals. There were a few, but all goalies have some. Largely, he made the saves he should and held up well enough on the tougher ones. That gave him a high floor and the Avs could work with that. That has not been his MO through his AHL player. Last night was certainly on the extreme side, but he's typically been a guy who has given up a soft goal in the AHL.
Given his physical skill set and how he's not a dynamic athlete... his games is going to have to be centered around not giving up soft goals. That's because he's simply going to get beat fairly often when things breakdown and he has to move a lot. No matter how good a team is, there will be those moments in the NHL. So he has to be rock solid on medium and low danger shots. We're talking 97-98+% on low and 90.5-91+% on medium danger... simply because he's unlikely to be a guy who can sustain over 82% on high danger.
This is simply one preseason game, so pure grain of salt. Just as we are watching him progress this season... he can't have the soft goals and stay as a reliable backup.