Embleton has started every league game for Sunderland this season having returned from his hugely successful loan spell at Blackpool in the second half of the 2020/21 campaign.
The 22-year-old's current deal expires at the end of this season and Sunderland are eager to find a resolution as quickly as possible.
Both Johnson and Sporting Director Kristjaan Speakman have spoken of their desire to secure Embleton's long-term future, and the Black Cats head coach confirmed this afternoon that dialogue has begun.
Johnson is eager for Embleton to keep his focus on footballing matters, and is hopeful that the talks will proceed positively.
"It's definitely in hand." Johnson confirmed.
"We're in contact with the representatives.
"From my point of view I'm obviously keen to protect that player-coach relationship, and continuing to help and aid him playing as well as I can.
"I really enjoy working with him, the likes of Embo, McGeady, Gooch, Pritch, Leon, it's a real pleasure to watch these guys and the things they can do.
"He's got to just concentrate on his football and his on-pitch stuff, and we'll let Kristjaan and the agents deal with the other side.
"I'm pretty sure there's an appetite to stay on his part, and our part there's very obviously an appetite to keep him on a long-term deal."
Embleton this morning was awarded the League One goal of the month award for August after his stunning strike in the 3-1 win over Wycombe Wanderers.
The attacking midfielder said he was 'loving every minute' of life on Wearside.
"It was a special goal for me because it was my first at the Stadium of Light in front of our own supporters, which is something I have waited a long time to do.
“It’s been a strong start to the season and we have implemented the way the gaffer has asked us to play, so hopefully we can kick on and keep winning. I’ve been here since I was six years old and this is my club, so I’m loving every minute.”