22-year old Alabama-born Johannsson, who grew up in Iceland, has been granted permission to represent the USA national team and could get his first opportunity when they meet Bosnia-Herzegovina in a friendly on Wednesday.
Another chance he has been given is to become the number one striker for Dutch club Alkmaar after fellow American Altidore left for Sunderland earlier this summer and he admits he is loving the extra responsibility.
"When I first came there [AZ Alkmaar] I was injured for the first 1-2 months so I had to spend time in rehab and getting back on to the pitch," he told USsoccer.com.
"I finally started to play but another American was taking my spot (laughs). Jozy was playing and scoring every game so I couldn't really complain. But when I got my minutes I tried to do my best and I scored three goals in five appearances.
"Now after Jozy was sold to Sunderland, the club sees me as the first striker. During the pre-season things went really well. We played three competitive games and I have three goals so far, so things are going good.
"AZ Alkmaar is a club that allows you to make mistakes and they will sit down with you and teach you what to do and what not to do. It's nice because it's a development club and they try to help you become the man you want to be."