The Brazilian centre-back arrived from Spanish side Villarreal last week and his task is now to attempt to get into Arsene Wenger’s first-team ahead of either Laurent Koscielny or Per Mertesacker.
Gabriel is a relatively experienced player who made 50 appearances for Villarreal having previously played 77 times for Esporte Clube Vitoria.
So what does Walcott think of his new teammate?
“I’ve only trained with him once and he likes to put his foot in, that’s for sure,” the England international said.
“He’s very tall. I didn’t realise how tall he was. Players that the boss plucks out seem to be good players so I’m sure he’s going to help us.”
Gabriel is Arsenal's second piece of January transfer business, after the club secured the signing of Polish midfielder Krystian Bielik earlier in the month.
There remains enough time for Wenger to make another move, with many fans believing an experienced defensive midfielder is a must as the Gunners attempt to push for more silverware. But whatever happens, they have signed a centre-back who has the talent and the time to become a future club great.