All eight Scots who featured for the Lions in the summer are included despite some not having played since.
There are also 12 uncapped players in the squad as Townsend freshens up his personnel for a testing autumn schedule. Among the new faces is Dylan Richardson, the South African-born Sharks back row forward, and a number of talented young home-based players including Glasgow Warriors’ Ross Thompson, Rufus McLean, Rory Darge and Jamie Dobie, and Edinburgh’s Marshall Sykes, Luke Crosbie and Jamie Hodgson.
There are call-ups too for the uncapped English-based duo of Sale hooker Ewan Ashman and Bath back-rower Josh Bayliss, and for Edinburgh loosehead Pierre Schoeman, who became Scottish qualified in the summer, and outside centre Sione Tuipulotu, who has made such an impressive start to the season with Glasgow.
For the opening match of the series, against Tonga a week on Saturday, Townsend’s selection will be limited to home-based players plus Richardson as the fixture clashes with a full programme of top-flight club games in England and France.
It means that Hogg, the Scotland captain, and the other non-home-based Lions - Finn Russell, Duhan van der Merwe, Rory Sutherland and Chris Harris - will only come into contention for selection from the Australia match, on November 7.
The quintet have been back playing for their clubs for a number of weeks, unlike the Scots-based trio of Ali Price, Zander Fagerson and Hamish Watson who have yet to play for Glasgow or Edinburgh this season.
Townsend, who was part of the Lions tour as assistant to head coach Warren Gatland, had first-hand experience of the toll it took on the players and struck a note of caution as he prepared to phase the eight Scots back into the Test environment.
“They had their own individual experiences, I feel they all had adversity to overcome,” said the Scotland coach. “From what I experienced they all overcame the disappointments, whether it was getting dropped, or not selected or picking up an injury. They were very positive in their actions, and their reactions.
“One thing we all have to be wary of is a Lions Tour can take a huge amount out of players, both physically and mentally. That’s what we have to be aware of this whole season, on the back of a very long and challenging season. The players are aware themselves, some are just coming back to play but Finn’s been back for the last six, seven weeks. We have to look out for those signs, if there is a mental and physical fatigue we’re going to support our players throughout a tough season.”
Hogg in particular experienced a roller-coaster tour in South Africa. He was forced to spend a period in isolation due to Covid and was then selected at full-back for the first Test in which he helped the Lions beat the Springboks. He retained his place for the second Test but the Lions lost and he found himself left out of the squad altogether for the series decider, which South Africa won.
Townsend believes the Exeter Chiefs man has taken the right steps to ensure he is coping both physically and mentally with the strain the tour took on him.
“It could be a concern, but having spoken to Stuart I know he’s on top of that,” said the coach. “He’s put a lot of things in place to prioritise his well-being.
“He asked his club for another two weeks of time at home which they agreed to. He trained on his own, and it was of a massive benefit to him and his family.
“Stuart is certainly a player driving that and making sure that when these challenges come on that are relevant to what’s happened these last 12 months, he’s got mechanisms in place to make sure it doesn’t affect him. We are aware that players are going to have challenges and we’re asking them to go again after such a big season.”