Lynagh, who made his Test debut against Wales, shortened his available holiday time, during which he had a tonsillectomy, to join the Reds upon their return to preparation earlier this week.
Lynagh told Rugby.com.au, "It's good to get back into the swing of things and get the legs working.
"We're all excited. It's probably the most excited I've ever been coming back into it. Just knowing what we managed to do last year and how good the vibes were around the place.
"Energy is high, and that's the way we like it around here."
Plenty of minutes in last season's Super campaign allowed Lynagh to help guide the Reds to fifth place, up from eighth, before they lost to the Chiefs in the playoffs.
Knowing that Reds rival James O'Connor has moved offshore to join the Crusaders, he has some breathing space to try to establish himself as the starting first five-eighths ahead of contenders Australia Under-20 five-eighths Harry McLaughlin-Phillips and Mason Gordon and Jude Gibbs.
There's also the prospect of a British & Irish Lions tour and the chance to prepare for the Super Rugby Pacific campaign with away games against Bristol and Ulster.
While he was happy with his performance during the 2024 season, Lynagh said he had much more to do in his play.
"Kicking's been a big part of my game, and [the Wallabies coaches] still want me to develop all kinds of areas, whether it's attacking, clearing or goal-kicking. That was one of my poor parts in the Super Rugby season and is a continuous work-on for me.
"Playing at the line and making right decisions is something I've been working on and I feel a lot more confident and comfortable doing that as well."
Lynagh said the Lions tour was a natural incentive for all of Australia's players, but he was determined to prioritise Super Rugby first.
"If I look after that, the rest will follow."