If Owens is ruled out of the 10-match tour, Hartley would seem to be an obvious replacement.
Wales hooker Owens will miss the Scarlets' Celtic League play-off clash against Leinster in Dublin on Friday because of an ankle injury.
Owens was one of three hookers named in the 41-man squad for the Lions tour of Hartley's native New Zealand, alongside Ireland captain Rory Best and England's Jamie George.
The combined side are currently holding a pre-tour camp in Wales before next week's training session in Ireland.
Their opening tour match is against a Provincial Union XV in Whangarei on June 3, with the first of three Tests against the world champion All Blacks in Auckland on June 24.
If Owens, who impressed in this season's Six Nations, is ruled out of the 10-match tour, England hooker Hartley would seem to be an obvious replacement.
Best, asked about Owens's injury on Thursday, told reporters: "From his point of view, to miss a semi-final is going to be gutting, and you just hope it is not too bad. I hope he recovers and he is fit to play in the final next week, or to train with us in Dublin.
"Ken is a fantastic player. He is very tough and very good around the pitch, makes a lot of tackles and does not miss many."
Best added: "He has been very good at the set-piece this season -- he is in fine form."
Meanwhile Lions assistant coach Neil Jenkins added: "It's rugby at the end of the day. Stuff does happen, and players get injured.
"Hopefully, Ken is going to be fine...With a bit of luck, everything is going to be OK for the Lions."
Hartley, capped 84 times, has led England to successive Six Nations titles under Australian coach Eddie Jones.
The Northampton front row is currently set to lead England on their two-Test tour of Argentina next month.
Hartley, who has missed more than a year of his career through suspension, was picked for the 2013 Lions tour of Australia but did not make the trip after being sent off in the English Premiership final for verbally abusing referee Wayne Barnes and and receiving an 11-week ban from the Rugby Football Union.
Lions coach Warren Gatland, speaking about Hartley's absence from the New Zealand squad, said last month: "Dylan is very unlucky in terms of not going."