But Wales assistant coach Jenkins, who played fly-half for Britain and Ireland's elite on the 2001 tour of Australia having starred from full back in South Africa four years earlier, doesn't reckon Rhys Priestland's season-ending Achilles injury means Sexton's selection is a foregone conclusion.
Instead, Jenkins both James Hook and Dan Biggar, who will hope to fill Priestland's Welsh boots this spring, and England duo Owen Farrell and Toby Flood could have a significant say Down Under.
"Jonny Sexton is an outstanding rugby player, whether it be for Ireland or for Leinster," said Jenkins.
"He dictates a game. He's very good defensively, very good offensively and an outstanding kicker.
"There is still a little bit of time to go before the Lions tour, though, and you look at the way Owen Farrell played against the All Blacks and how he has been going recently.
"I'm also a big fan of Toby Flood, who I think is an outstanding player. I'm sure he will have a lot to say about that as well and I'm sure our two 10s here in Wales will have something to say, whether it be James or Dan.
"I'd like to think the both of them, whoever is going to play in the Six Nations, will put their hand up as well."
Jenkins is certainly expecting a tough selection call for interim Wales coach Rob Howley when it comes to naming his No10 for the Six Nations opener against Ireland a week on Saturday.
Hook has the greater international experience and was a Lion in 2009 but Biggar's recent showings were leading to calls for him to be given a shot even prior to Priestland's injury setback.
"The shirt is up for grabs, obviously with Rhys being out injured," added Jenkins.
"I think it's all about who turns up, fronts up and trains well - they will get the nod.
"Both are exceptionally talented players. I think we are quite lucky to have them battling it out for that shirt.
"It's going to be a great battle between the two of them."