The Republic of Ireland international endured a difficult season last year as he fell behind Simon Mignolet in the pecking order but has established himself this season
Westwood struggled to dislodge Simon Mignolet last season but, with the Belgium international joining Liverpool and the arrival of Vito Mannone at the Stadium of Light from Arsenal, the 28-year-old said he was determined to "cement" his position in the team.
"I came back raring to go and looking to this season to put a marker down and cement my position," he told the Sunderland Echo. "Thankfully for me, my hard work has paid off and I've started the season."
He continued: "You've got to have belief in your own ability. Last season was really tough to be fair, but hat's off to Simon, he had a great season. At times, you can hear the voice of reason and Simon was our player of the season.
"There were no gripes from me or animosity towards Simon. We got on great. I helped him as much as I could and pushed him as much as I could."
However, despite securing his place in the team, the Republic of Ireland international was left disappointed after the Black Cats narrowly lost 1-0 to Fulham in the opening game of the season
"Of course there were mixed emotions," he said. "I was delighted on a personal level obviously to start the season, that's what I was aiming for and what I've worked hard for.
"But by the same token, the result was terribly frustrating. They had one opportunity and it cost us really with a real sucker-punch."
Sunderland's next game sees them travel to St Mary's to take on Southampton in the Premier League on Saturday August 24.