Matthews, 23, who spent the last four years at the SPFL champions, admitted: “Dick Advocaat said: ‘We’ve been watching you for a while and I like what I see. But you’ve got to work on a few things and, hopefully, I can make you a better player’.
“I’m sure he’ll be able to do that and with the players here I can only improve. I’m very excited to just get started.
“I like to attack. but the manager has already told me I need to work on my defending ,so I’ll try my best to do that.
“I like to get on the ball, I like to get forward and, hopefully, score a few goals.”
Matthews could make his Sunderland debut in Thursday night’s first pre-season friendly at Darlington before the Black Cats jet off to North America on tour.
“I’m obviously a bit nervous. Its a big change for me, but I’m sure they’ll make me feel welcome and help me improve as a player so I’m looking forward to meeting them all.