James Ryan is an injury concern for Ireland for the summer internationals against Japan and the United States on 3 and 10 July in Dublin.
The Leinster second row was named as captain for the two Tests at the Aviva Stadium when head coach Andy Farrell announced a 37-man squad for the games.
Ryan, 24, has an adductor issue and will be monitored to determine his availability to face Japan.
Ulster’s Michael Lowry will continue to train with the squad this week.
Ryan was expected to be in the running to replace Alun Wyn Jones when the Lions skipper withdrew from the squad to tour South Africa with a shoulder injury on Saturday.
The Ireland lock missed out on initial selection for Warren Gatland’s panel.
Ireland are without their contingent of seven British and Irish Lions squad members for the matches against Japan and the US, while regular skipper Johnny Sexton, Keith Earls and Cian Healy were not included in the group for the summer Tests.
Garry Ringrose withdrew from the squad last week with a shoulder injury which requires surgery and his place was taken by uncapped Ulster centre James Hume.
Twelve uncapped players have been included in Farrell’s squad for the matches, with the team to face Japan on Saturday to be announced on Thursday.
Japan will come into the game on the back of a 28-10 defeat by the British and Irish Lions at Murrayfield on Saturday.
The Brave Blossoms were 19-12 victors over Ireland when the sides met in the group stages of the Rugby World Cup in September 2019.