The Sky Blues were downed 1-0 by their crosstown rivals at Jubilee Stadium, with Redmayne unable to stop Mitchell Duke's 81st minute header.
It was not an ideal result for Sydney ahead of Wednesday's return to Jubilee, where they will face the perennial K-League champions, Jeonbuk Motors, in their second game of the AFC Champions League group stage.
But Redmayne says manager Steve Corica kept Friday's defeat in perspective, especially given the defending champions maintain a 10-point lead at the top of the A-League with two games in hand.
"The message from Steve was still really positive," Redmayne tells Tribalfootball.com.
"We didn't execute on the night but again we created a wealth of chances. You can look at it as we're ten points clear and two games in hand. To go a season undefeated is nice but you have to be realistic, you're going to lose some games.
"Unfortunately we've lost two games this season and they've both been to our rivals. But there are bigger fish to fry. We know the journey is right and we know what we need to achieve this year and we're fully focused on that."
Corica's side must also overcome a loss to Yokohama F. Marinos in their opening AFC Champions League group match.
The Australians were ruthlessly dispatched 4-0 by Yokohama, which adds further weight to Wednesday's meeting with Jeonbuk, who also lost to Ange Postecoglou's outfit in December.
Redmayne believes his team were unprepared due to missing two matches because of this summer's bushfires, rather than being impacted by the level of competition in the AFC Champions League.
"Nah I don't think so. The last game we were a bit underdone because we hadn't played in two weeks. We were bit out of rhythm, a bit out of touch, so to speak.
"I think we'll be better for the two games that we played leading into tomorrow night."
"Yeah I can't wait. I love playing at Jubilee, it's just a fantastic ground. And it's one we've kind of created a fortress at. Having said that, Friday night was a disappointment, but we've got a fantastic record.
"And the fans we have down there really embrace it. It's close to the pitch and we can kind of give back to them after the game and hopefully the performance is what they want as well."