Lescott moved to the Baggies after leaving Manchester City in the summer, and after the England international helped his new team to victory at Tottenham Hotspur on Sunday, Foster has admitted that the centre-back is having a positive impact on his teammates.
The 31-year-old told the Express & Star: "A lot of lads spark off Joleon. He has got that bit of an aura about him. All the lads around him raise their game when he's there.
"Fair play to 'Joe', the way he read the game on Sunday was absolutely incredible. His vision is fantastic and it's nice to have players like that in front of you."
Lescott had previously missed the opening month of the season through injury.