The Venezuelan forward, who has scored three out of the Baggies derisory season total of 14, went down during the 0-0 draw with Everton on Boxing Day.
"We can't afford to lose players so we are sweating on him a little bit," Pardew added.
"He's been very important since I've been here as well as under Tony [Pulis]. He's a big player.
"But it's difficult to understand why we haven't won that today but we go to the next game.
"It was a sound performance, our fans were brilliant and with us, we thank them."