Newland is immediately available for selection after arriving in Ireland on Tuesday. The Leinster team will be announced on Friday lunchtime.
Commenting on Newland's arrival, Leinster Forwards Coach Jono Gibbes said: "We're pleased to sign Clint and he will add experience to the group in place of the injured Stan Wright who, in recent seasons, has been the scrum leader in the Leinster pack."