Regarding Andrei Markov, some posters, and some broadcasters last night, remarked that he looked awkward at times, far different than the smooth skater we've come to know. I will take for granted that there are no issues in terms of pain, swelling, looseness in the knee, or else the docs wouldn't have let him jump on the ice.
One issue Andrei will work through is a lot of scar tissue in the knee, which is collagen inside the joint kind of binding some pieces that should move smoothly. A lot of this is worked out during rehab, but there's always some left before you return to full duties and he will break up this scar tissue by playing. The stops and starts and sudden stresses on the knee that you can't replicate in training will take care of that.
Another reason, which I think is even more important, is that Andrei has been 'guarding' his knee for essentially two years now. He has been careful to not put too much strain or weight on it, has been limping to protect it, would gasp and fall off it if he made a weird move that would give him sharp pain. All these habits and reflexes have been ingrained in him for so long that it will take time for him to learn to trust his knee, to not be afraid to push it, and to have these reflexes and habits diminish and disappear.
Until then, we can expect Andrei to try a quick pivot, feel a twinge in his knee, which is normal as scar tissue is being broken up and the joint being stretched in a manner it hasn't been in a long while, and have him stop skating or fall to the ice in anticipation of pain or further damage.
Josh Gorges very early in the season had a collision where he fell in the corner with his reconstructed leg underneath him, and he winced and cringed in anticipation, as did we before our plasma screens, but after skating off to the bench, gingerly testing his knee, he realized that he was okay, and we haven't seen him guarding his knee since. Not hoping for such an awkward fall for Andrei, but an accumulation of moments like these which will reassure him that his knee is fine, and convalescence is behind him.