I think Gabriel is, or can be, a decent enough no. 3 or no. 4 but Mustafi seems like different class to him. A football agent who's a friend of mine maintains he is a huge signing. Tbf he also thinks Lucas isn't good enough for the Arsenal.
To be fair, you don't need an agent to tell you that. A ten year-old son with a laptop and PES works just as well, scouting-wise.
"Plenty of strikers can score goals," he said, gesturing to the famous old stands casting shadows around us.
"But a lot have found it difficult wearing the number 9 shirt for The Arsenal."