After impressing the Baggies boss in training, Harper travelled with the first-team squad to the King Power Stadium on Sunday for his first taste of Premier League match day preparations.
Although he wasn't named in the squad, his shirt was hung up in the dressing room and he trained on the pitch beforehand.
Pulis did this last season with Jonathan Leko, Sam Field and Kane Wilson in order to acclimatise the youngsters to the unique experience.
Albion have high hopes for Harper, who has been converted from a striker to a versatile box-to-box midfielder, is capable of playing any central position, and has an eye for goal.
A regular for James Shan's under-23s, he scored a clinical volley in the 5-2 victory over Aston Villa in Premier League 2 earlier this season and has also featured in all three Checkatrade Trophy matches.
"Rekeem travelled with the first-team squad on Sunday, which is brilliant," said Shan. "It's a real positive and a huge reward for the academy.
"He was a number nine in the school boy programme, but he's been turned into a midfield player because of his physical attributes.
"He's got a range of abilities. He can be a classic box-to-box midfielder like Patrick Vieira, he can play in a two or a three.
"He can play holding midfield, number 10 or number eight. He really is a talent who has got a lot of potential and the good thing is he's working hard at his game."
Harper will no doubt be encouraged by Pulis's continued trust in Albion's young talent.
The Baggies had three teenagers on the bench at the King Power Stadium, and even though Leko, 17, Field, 18, and Wilson, 16, didn't get on the pitch, all three have featured for the first team this season.
Shan has witnessed first-hand the impact that has had on the rest of the academy players, the confidence it instils in those youngsters willing to work hard and the message it sends out to the club as a whole.
"When the manager first came into the football club, he said he would pick anybody good enough," said Albion's under-23s boss. "He's not concerned about age, if they're good enough they'll be around the match day squad.
"For those three to all make the squad against Leicester was brilliant but the bigger picture is that it sends a fantastic message to the academy players that there is a pathway there.
"It's really pleasing and really good that they're in and around it.
"There are always a watchful pair of eyes from senior first-team staff coming to our games. It's good that they can impress them.
"We have that at every home game and some away games. It's a real positive for the players."
Shan isn't afraid to throw youngsters in at the deep end either.
In this week's Checkatrade Trophy match against Gillingham he brought on 15-year-old Jamie Soule as a substitute.
The England youth international played five minutes at the end of the 2-0 defeat at The Hawthorns.