The Baggies are lying in seventh spot in the Barclays Premier League after collecting 33 points from the opening 20 matches.
But Foster insists head coach Steve Clarke will make sure there is no easing back even though a top-flight spot for another campaign is already virtually assured.
He said: "The gaffer is very big on not resting on our laurels. I know we've got 33 points and we probably look safe for the season - but that's not what we're aiming to do.
"We're trying to replicate the first half of the season and, if we can do something like that, you never know what can happen.
"We will just keep doing what we're doing. The gaffer is very good at not letting us get carried away or looking at this or that. We will just go about our business and see what's what."
Albion will be looking to make amends for one of their poorest performances of the campaign, a 3-0 defeat at Craven Cottage in September, in a game where Peter Odemwingie was red-carded.
Foster said: "I don't think that result will affect us at all because there were strange circumstances in that game, including the sending-off.
"I just think we played rubbish on that day. We were so bad that 3-0 was a good scoreline for us because they absolutely hammered us.
"But it's a good few months down the line now and we've adjusted a lot more now so they will be coming to our place fearing us much more than we're fearing them."