The 23-year-old winger joined Cardiff on a season-long loan early last month and has since started all four Championship games.
Ojo impressed in his side's 2-0 victory over Nottingham Forest - Cardiff's only win of the season so far - but he is yet to register a goal or an assist.
“Sheyi has got unbelievable ability," said Harris after last weekend's 0-0 draw against Blackburn. “We have to fill him with confidence and let him be himself."
“Sheyi, Josh Murphy, Tomlin a little bit, they are going to give the ball away at times, but we have to appreciate they have great quality in the final third. But his work tracking back in particular was a top effort."