Both sides have found it difficult to register victories since making respective managerial changes, with Pepe Mel yet to win as West Brom boss and Monk's solitary triumph coming against local rivals Cardiff City in his first match in charge.
The Hawthorns outfit, who have won just once on the road this season, sit perilously above the relegation zone on goal difference, with Swansea four points better off in 14th.
And Monk believes this weekend's clash will be huge for both sides.
"You get defining games throughout a season, and this is definitely one of them," he said. "We want the three points and so do West Brom.
"It's a good game, a big game, but we're in front of our home fans and it is important that we put on a performance to get the win."
This fixture last season produced one of Swansea's most scintillating performances under former boss Michael Laudrup as the four-pronged attack of Michu, Nathan Dyer, Pablo Hernandez and Wayne Routledge ran riot.
A Michu strike and a Routledge double saw the hosts 3-0 up by the 39th minute, with Romelu Lukaku netting West Brom's only reply on the stroke of half-time.
Furthermore, this weekend's hosts claimed a 2-0 victory at The Hawthorns in September - a win that kicked off Swansea's strongest run of the season so far, with a draw against Liverpool and triumphs at Valencia and Crystal Palace following soon after.
The men from south Wales welcomed Michu (ankle) back to full training this week and Monk is set to make a late call on his involvement in the matchday squad, while Hernandez is also a doubt. Monk expects Jonjo Shelvey (hamstring) and Kyle Bartley (hamstring) to be out for another week and fortnight respectively.
Jordi Amat is likely to start alongside Ashley Williams at the centre of defence as Chico Flores starts a three-match ban for a challenge that led to an equalising penalty in the 1-1 draw with Crystal Palace last time out.
Mel, meanwhile, has a lengthy list of absentees, with Chris Brunt, Steven Reid and Diego Lugano all sidelined by knee injuries, and Billy Jones and Claudio Yacob suffering hamstring problems.
"Of course, the injuries give other players like Graham Dorrans, Scott Sinclair and Craig Dawson a chance and I believe they can help us," said Mel.
Nicolas Anelka remains suspended following his controversial 'quenelle' gesture.
