Raynor, 48, made 80 appearances as a midfielder during a two-year spell at Preston in the mid-90s and feels the expectation levels at Deepdale could work in his current side's favour.
"I had a fantastic time at Preston as a player, some real great memories including the play-offs at Deepdale," Raynor said.
"Preston is a very big club for League One and they have a superb support, but what comes with that will be a huge expectation for them to win promotion to the Championship via these play-offs.
"The supporters at Deepdale will be demanding that they are promoted and given the size of club they have every right to be like that, so I suppose all the pressure is on them."
The Millers take on Preston at Deepdale in the first leg on Saturday and play the return at New York Stadium a week on Thursday.
Raynor added: "They will also have the backing of almost 20,000 fans inside Deepdale, so that also has its advantages, but having played for those Preston supporters they will also be demanding of a top-class performance."
Source PA