Howe says he has support from club despite Newcastle's dire run
The Magpies will run out for the third-round tie at the Stadium of Light having lost seven of their past eight games and their most recent four in all competitions.
The dire run has led to speculation that Howe's future as head coach at the Saudi-backed club could be uncertain after two years in the post.
Newcastle, who finished fourth in the Premier League last season, are struggling in ninth spot and are already out of the Champions League and the League Cup, but Howe said he still had backing from the club.
"I certainly don't need daily reassurances," he said on Friday. "I feel comfortable in the fact that we are working as hard as we can to improve performances and improve results.
"Obviously I know it's a results-based business - all the usual things you'd expect me to say - but I do feel the support from the club, and that's really important in this moment."
Saturday's fixture will be the first match between Newcastle and Championship side Sunderland since a 1-1 draw in the Premier League at St James' Park in 2016.
Howe said a win at the Stadium of Light could rekindle his team's faltering campaign, admitting he is aware of "what this fixture means to everyone".
"It can certainly reboot us and just change the external - and even internal - view of ourselves because it can change very quickly," he said.
"I have made reference to it many times. The Manchester United game, our best performance of the season, was not that long ago and now the view is very different on the team.
"Confidence is a very fragile thing for the players as well, so anything that helps them re-find their best rhythm as quickly as possible is what we're seeking."