The text says while he looks at his phone: (God damn you! I can't believe they sacked the last guy for this clown!)
Of course is an assumption that he means Grayson as it is not stated clearly. Then, it's more plausible I think that it's Grayson as Gascoigne said he backed us for the position instead of Grayson.
Heh
Let me explain.
This part isn't about Grayson, but it's about football (soccer if you're american). When you first met him in his office, you can see his mug with the logo of Tottenham Hotspur, so I assume he is a fan. Then, when he is looking at his phone during the meeting with Brodie's dad, the last guy he is speaking about is Mauricio Pochettino, the former manager of Tottenham, who was sacked and the new guy, also called by him "The Special One" or clown is current Tottenham manager, José Mourinho.
So it's not about the Greyson or the events from the game, it's about events from real world and it's just some funny mention
(And I hope i'm not mistaken with this, but for me it's quite obvious this section)