The 28-year-old admitted while on international duty last month that might have to consider leaving the Black Cats in search of the regular football he needs to regain his place as the Republic of Ireland's number one.
However, Mignolet's departure for Liverpool means there is now a vacancy, and the former Coventry man and new signing Vito Mannone will fight it out for the right to take over from the Belgian.
It is an opportunity Westwood is relishing after his hopes of securing a loan move in January were scuppered.
He told the Sunderland Echo: "It would have been a wrench to leave, but on the other side of it, I have to think of my career.
"I have to play games and have something to look forward to during the week, putting all that work in on the training field to send fans home happy on a Saturday.
"I didn't have that last year, but I still carried on going. At times, it was mentally demoralising.
"I want to play. Everybody knows I want to play. It's not in my nature to sit on the bench. I would rather go and play for a Championship team on less money and play every week, just so I get that buzz on a Saturday.
"Sitting on the bench in the Premier League and picking up money is not my desire or attitude. It's a trap I don't want to fall into.
"You can quite easily do that. You can see over the years that players have done that, not just goalkeepers."