Stan Wawrinka pushed himself quite a bit this year, hoping to reach a certain level he wanted to reach before the start of the season.
Wawrinka had a couple of big injuries in recent years and almost ended his career. The Swiss veteran opted to give it another try, and he played really well at times despite everybody and himself knowing that any serious level is likely never to be acquired again.
He still pushed, believing himself to be good enough to be competitive, and he was, for the most part, really competitive. Recent weeks haven't been so great for him, though, with a couple of early exits, including from the Swiss Indoors a few days ago.
After the match, Wawrinka admitted that it's been a struggle for a while now as he was feeling quite drained, explaining that it likely has to do with him pushing himself quite a bit early in the year. It makes sense because he's not the youngest anymore, nor did his body avoid a beating over the years.
I feel that for the past few weeks, I have been very tired, broken even. After Astana, there were two or three times when I wanted to work but I couldn't because I was too tired.
I feel like I'm paying back for all the efforts I've made since returning from injury. I really wanted to get back to a certain level & I had to push myself as much as possible to do that.
We'll see what happens with Wawrinka in the coming months, but as of now, it's unlikely that he's going to retire from tennis. He'll likely play next year, but the way he does will likely determine how long he keeps pushing. I don't see him playing much more than next year.