Sano for only playing a third of the season has put up monster numbers. He hasn't looked good in Houston but otherwise has been tearing it up. Even while injured. If he had played the whole season he would have Pujols type numbers.
He had some good years after getting paid. What he hasn't done is be the same player post concussion. Really sucks for a franchise that had the same thing happen to Morneau just a few years earlier.
He's had a few injuries but he and the team say he is fully healthy. Further they also moved him from catcher to preserve his health and still doesn't look like the batter he once was.
Injuries, now he does not catch anymore because of injuries, and like you said, concussions were severe. Is a pity as he was a great player, and hell of a hitter. Now he is an average player with a big contract.
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Jed Lowrie's was the first <a href="https://twitter.com/hashtag/Astros?src=hash">#Astros</a>' grand slam by a non-catcher.</p>— Chandler Rome (@Chandler_Rome) <a href="https://twitter.com/Chandler_Rome/status/640627059732152320">September 6, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> <blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Chad Qualls will pitch the <a href="https://twitter.com/hashtag/Astros?src=hash">#Astros</a> ninth inning. Dallas Keuchel, on the hook for his 14th straight home win: 8 IP, 5 H, 3 ER, 2 BB, 12 K</p>— Chandler Rome (@Chandler_Rome) <a href="https://twitter.com/Chandler_Rome/status/640628158304268289">September 6, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
Since coming off the DL, Qualls has given up a run in 5 of the 22 games he's pitched in (one of those being when he was brought in w/the bases loaded & nobody out and threw 1 pitch). He's allowed a baserunner in 11 of those 22 games.