The 26-year-old has contributed two goals and two assists already this season, offering the Owls attack a fresh dimension with his pace and trickery, and many Bluebirds supporters were disappointed to see him leave after he produced a handful of promising performances in the Premier League last term.
Speaking ahead of Harris’ return to the Cardiff City Stadium on Friday evening, his former boss Neil Warnock praised his former player’s impact in south Yorkshire.
“He’s given them directness, pace and power," Warnock said. “He’s got every attribute. I can’t praise him highly enough.
“We had a chat last year, around Christmas time, and he trained like a Trojan. We have been blessed with good wide players and he just couldn’t get a long run.”
Warnock admitted he had been open to keeping Harris on at Cardiff as his contract began to run down, but said a deal couldn’t be reached, describing his departure as ‘mutual’.
The 70-year-old former Sheffield United boss said: “He needed a run of games and when we spoke about his contract at the end of the season, his father represented him, and the sort of money they were talking about, he had to be a regular in my team. And I didn’t feel I could 100 percent assure him of that.
“What we could offer him, he could get a lot more elsewhere and he could play. So there’s no real issue to me and I said 'good luck to you'.”
Earlier this week Wednesday boss Garry Monk admitted his admiration for Warnock, who responded in kind.
“I’ve always got on well with Garry,” he said. “From our first battles I’ve always kept in touch with him. He’s had a number of clubs and different experiences. That’s what you do as a manager.”
Asked whether his Blades connections adds anything to his clashes with Wednesday, Warnock said: “Possibly it brings something extra for me. It’s always nice to play Wednesday, my sister is a Wednesdayite.
“It is special. They’ve got a decent team and have had a good start.”