Exeter prop Tomas Francis is also training with Wales.
Owens, 28, who was ruled out of the start of the tournament by a neck injury, has made a successful return for his region.
Francis, 22, is one of the heaviest forwards in the professional game at 6ft 1in and 21st.
Gatland names his team to face Ireland on Tuesday.
Owens is challenging incumbent Scott Baldwin, of Ospreys, and long-time rival Richard Hibbard, of Gloucester, for the Wales number two jersey.
Francis would have to leapfrog Scarlets' Samson Lee, Osprey Aaron Jarvis and Cardiff Blues' Scott Andrews in Wales' pecking order to cap a remarkable rise from virtual unknown to Test player.
Wales defence coach Shaun Edwards says Exeter's set-piece play helped bring Francis to their attention.
"He's a big kid and the Exeter scrum has been excellent recently," he said.
"His scrummaging is absolutely outstanding but he's also a skilful player as well.
"He's big, he's young and he's coming from a great environment.
"Exeter is a place where they pride themselves on hard work and we would like to think we're a similar sort of environment."
National coach Warren Gatland mentioned his interest in Francis before the tournament began.
Francis has previously played for Doncaster and London Scottish and qualifies for Wales via a grandparent born in the Swansea Valley.
Wayne Pivac, who coaches Owens at Scarlets, said after Saturday's 23-13 Pro12 win over Leinster that Owens was ready for a Wales recall.
Wales lie third in the table, level on points with England and two points behind unbeaten leaders Ireland, the only team who can complete a Grand Slam.
Gatland's side lost 21-16 to England in their opener, but regained title hopes with successive wins over Scotland and France.
Wales have called Scarlets hooker Ken Owens into their squad before Saturday's Six Nations match against Ireland.