Aston Villa manager by insisting they are favourites to progress to the Championship play-off final.
Smith said West Brom's recent Premier League status, plus their consistent place in the top-six throughout the campaign, means they should be viewed as the likelier side to reach Wembley.
Many observers have picked Villa to return to the top-flight after a run of 10 successive victories propelled their position up the table but Smith wants to paint his team as underdogs.
'I've heard people saying that Villa think they're at Wembley already, far from it,' he said. 'West Brom have been in the play-off places a lot longer than we have.
'There's several pundits out there saying we will be the favourites, but they're the ones who have been above us.
'They've been ahead of us all season, they came down from the Premier League with a team full of Premier League players. They're the favourites, we have to spoil their party.
'Our job has been to focus on each game as it comes. We're confident without being over-confident, simply because of the run we're on.'
The local rivals meet at Villa Park in the afternoon kick-off on Saturday, before going to the Hawthorns for the second leg on Tuesday night.
Despite the FA Cup quarter-final of 2015, which ended with thousands of Villa fans running onto the pitch in celebration and West Brom supporters hurling seats, these coming encounters have been billed as potentially the biggest in the clubs' histories.
But Smith, a boyhood Villa fan, provided a counter opinion. 'I'm not sure about that,' he said. 'I remember being there in 1981 when there was 47,998 and Brendan Batson's back-pass gets stopped in a pool of water and Peter Withe slots one home.
'Albion might have been third or fourth at the time and Villa went on to win the title, so perhaps that game was bigger. But with the funds available now and the prize of getting in the Premier League, it's certainly a big game for both clubs.'