The experienced Italian centre-back only arrived at Vicarage Road last year from Udinese, and has enjoyed an impressive debut campaign in the Championship.
His 40 outings – with eight goals – have attracted both West Ham and Southampton, who are rumoured to be looking to offer the 25-year-old a chance at life in the top tier.
The duo are said to both be on the lookout for defensive additions this summer, and see the classy enforcer as a good option.
Watford are likely to resist offers after tying their man down to a five-year contract upon his arrival, but the lure of Premier League football may be enough to turn Angella’s head.
The Hammers are thought to be front-runners with Winston Reid’s future up in the air, but Southampton may have cash to spend with star names such as Adam Lallana and Luke Shaw looking likely to move on.
The Italy U-21 international has endured a stop-start career, which started at Empoli.
From there he joined Udinese in Serie A, but he was unable to cement himself as a first-team regular before being sent on loan stints with Siena and Reggina.