I initially came to that conclusion but then thought it wouldn't be much of a "shock" as he's been in full training for over a week now.
To me, the word "shock" suggests someone completely left field (bad pun intended) which would lead us to the likes of Reeves or Chanbers as mentioned above.
There again, without seeing the context of the Tweet in question and the posting history of said Tweeter we're obviously in pinch of salt territory here.