He wanted this enough to make the calculation and played around his injury with more aggressive play to end points quickly. As he ages, this approach may become his way of extending his career.
Here a doctor suggests it wasn't that bad.
AO Chief comments regarding Novak injury under a Microscope
Anyone judging a hamstring tear must have never suffered a hamstring injury. It is debilitating and lethal to your ability to move. Fear of making it worse can make you tentative. Novak took a different approach and went for winners knowing he had to end the points earlier.