The France international made an impressive start to the 2017-18 season with two goals and two assists in their opening four Premier League games.
However, Pogba suffered a hamstring problem during their opening Champions League fixture to curtail his form and keep the midfielder sidelined until November.
De Bruyne, on the other hand, has netted seven times and has made 15 assists in 31 games in the Premier League in the current campaign.
The Belgium international has helped Manchester City to build a commanding 16 points lead at the top of the table, with Manchester United their closest rivals.
Pogba has struggled to hold down a starting spot in the Manchester United team under Mourinho in recent weeks to raise questions about his future.
Former Manchester United defender Parker delivered his withering verdict on the difference between De Bruyne and Pogba.
“The gap between Pogba and De Bruyne could end up a nineteen point gap,” said Parker, speaking exclusively to 888sport.
“We’re talking about potential up against class. There are good players but to become a great player you have to do it consistently week in and week out and that’s what de Bruyne does.”
Manchester United will make the short trip to Manchester City in their next Premier League game on Saturday afternoon.
The Red Devils lost 2-1 to Spanish side Sevilla in the Champions League round of 16 last month.
Read the full 888sport interview with Paul Parker, including his prediction for the Manchester Derby this weekend
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