Foster was named in North End's defence for the Johnstone's Paint Trophy tie at Bury on Tuesday night shortly after his move to Deepdale on non-contract terms was confirmed.
The 27-year-old, who previously played under Westley at Stevenage, acquitted himself well despite the 3-3 draw before the Lilywhites' penalty shoot-out triumph not being the idea night for defenders and he is battling to keep his place for the weekend trip to Coventry.
"He was brilliant," said Westley. "What a debut from the lad. He's played for me before and I know that he's a lionheart who'll put his body on the line and he'll fight with everything that he's got.
"He had an outstanding game, there's no question. We let three goals in but his positional sense, his fight in the challenge, his honesty, his organisation were big parts of what we did."
- Sports & Recreation