Promoted Huddersfield, 13th on the league table, have collected eight points from five matches at the John Smith's Stadium, including a shock 2-1 victory over second-placed Manchester United last month.
Wagner reckons his men have proved themselves in their opening 10 matches of the season and he is confident of a positive result against Tony Pulis's West Brom side, who have only won twice in the league this season.
"We have a lot of respect for West Brom but we have enough confidence in ourselves to be a competitor and have a chance to get a result," Wagner told a news conference.
"Home form and home points are crucial in the Premier League. We would like this to continue consistently.
"We've shown we are competitors in the Premier League and we will try everything to be successful."
When asked if he could guide the club to consecutive home wins in the top flight for the first time since November 1971, Wagner replied: "We have always tried to make the unrealistic, realistic at Huddersfield and we will continue to do so."
The manager also confirmed winger Rajiv van La Parra was fully fit, saying the 26-year-old's early substitution at Liverpool last weekend, with what appeared to be a groin injury, was only made as a precaution.