It makes sense now as to why someone that is usually an excellent skater, was exposed so easily and so often. You can only imagine the amount of numbing agent and freezing Nurse used throughout the playoffs to tolerate the pain while playing 25+ minutes every night.
Obviously Nurse isn't the only player playing with severe injuries, as Draisaitl played with multiple injuries as did several players during the postseason, but for a defenseman, having a torn hip flexor is a major issue when you spend the majority of the game pivoting forwards and backwards. I'm no doctor, but from personal experience, if your hip is out of alignment, then your knee and back are too. For someone that plays such a physical game, that could only make things worse, not having the stability in your lower body to take some of the contact you would normally be able to.
Nurse and Drasaitl are just two more examples of why hockey players are often called the toughest athletes in the world. It wouldn't surprise me if Nurse has surgery in the coming week or so to clean everything up and make sure he's ready for training camp.