Villa are the underdogs heading into the game because of the very different Premier League positions of the two teams, but Westwood feels the club need to relish that and back Tim Sherwood to develop a good game plan.
“The pressure will be on them. They're looking to win a trophy. I'm sure the gaffer will have a game plan, we'll stick to that and I'm sure it'll do the job for us,” he said.
“We think we can win. We believe we can beat them. If people are saying we're underdogs, we'll relish that.”
One of the first changes that Sherwood looked to make when he arrived at the club as a replacement for Paul Lambert, was to take the pressure away from his players.
Villa have produced their best under Sherwood when they have had something to aim for and the freedom to maximise their main strengths.
The last two performances have been difficult because the club had already achieved much of the hard work needed to secure their safety in the Premier League.
This weekend the focus is back and the team have a trophy to aim for and a clear incentive to win a single game of football.
Sherwood’s game plan is unlikely to be based around sitting back and defending deep because if Villa do that, they will be picked off by a very talented and experienced Arsenal team.
The message will be clear; the pressure is on them, get on the front foot and make sure they feel it.