By Anthony Marshall - Newcastle United Managing Editor
The Baggies travel to Tyneside for a 5.30pm kick-off in the Barclays Premier League, as United go in search of their fourth consecutive victory - a result which could lift them into the division's top six.
But while the boss may not have settled on his starting line-up just yet, he is certain that centre-back Williamson - who has been outstanding over the last couple of months - will be in from the off against Albion.
"All my defenders have got a fight on their hands at the minute because they are (all) playing so well," explained Pardew.
"When you are winning games it is difficult to change it so it's a tough call for myself on that one.
"I've got really good players who aren't playing at the moment, and I try to do my very best to keep them in a good place for when they are going to be called upon. And when they are called upon, they need to grasp their opportunity.
"Mike Williamson is an example of somebody who wasn't anywhere near the first team for periods of this season, finds his opportunity and takes it.
"He will play on Saturday, 100 per cent."
But Pardew believes quality replacements are crucial to help change games or see them out, and predicts that a substitute could become a hero this weekend.
"There's a good determination amongst the group to continue our run," he said.
"We have great assets on the bench most games now and they can make the difference.
"This game could certainly be won from the bench on Saturday because we've got major players on there and so have West Brom."
Tickets for Saturday's Barclays Premier League fixture against West Bromwich Albion are still available, starting at £15 for adults and £5 for concessions. To secure your seat, click here