Edler has obviously declined.
There was time when he was a lock for the Swedish National Team and now he isn't even a consideration.
Biggest problem is the skating and that may be due to the back issue. He has lost range in his play and now plays it safe. Rarely, if ever, does he join the rush and any offense he has now (outside of the occasional backdoor play on the power play - which he has butchered all season) is restricted to point shots.
This reduction in his mobility is clearly evident in the 3 on 3 play. If this was the Edler of previous year this would be his bread and butter. As it is, he hasn't got the speed to be a factor. Another indication is the declining point totals. His offensive production this year is anemic (1 goal 3 assists) and nothing like that of upper end NHL defense man.
On defense he doesn't have the huge backward cross over that allowed him to take people wide and eliminate them. Now just tries to keep inside position. Also, you note how he straightens up and doesn't maintain proper hockey stance which sometimes makes him slow in reacting around his net or to players cutting to the net.
Edler is still strong and if he can lean on someone he can still come up with the puck. He also retains good up ice vision and can make the good pass out of his zone
But, overall, the skating issues have reduced Edler to pretty much your garden variety stay at home defense-man. He doesn't force the play in the mid ice area and for that matter doesn't seldom pinches. Nor does he try to pack the puck much or carry the puck, with speed, out of his zone. (One of the many factors that cause the Canucks to be tied up in their zone too much). I never see Edler leading the rush out of his end and I do see him more and more backing off his blue line.
Use to be the Edler would have a few sub par games but now he can have some just brutal games. In other words, when he was off his game, before, still not bad but when off his game now he can be very bad.
Moreover, it seems to me, the criteria in judging Edler has changed. When he has decent defensive game (and, in my mind here, he is not doing much more here than any bona vide NHL defense man does) many people say he is doing well. It is like we don't even consider any longer if he did much offensively. In earlier years Edler would be judged by a standard where the good defense was assumed and people looked more to his offensive contributions to determine if he was good or bad..
Maybe the leg, or more likely the back, but Edler skating has weakened and with that his range and mobility have suffered. When you see him taking maintenance days you have to know he is working on problems that are probably chronic and will continue to hurt his play.
At this point, Edler is a good enough d-man to play, at least, adequately in his own end most of the time. On a good team where his responsibilities were limited he would an absolute benefit (as he is still with the Canucks). But he he is no longer close to the #1 category. At one point he was, now he isn't, and I don't see how you can call that anything else but a decline.
Given the present status of the team (a team in dire need of a rebuild and probably several years away from contending), he needs to be used too get younger assets.