Dylan Hartley has been replaced by Rory Best in the Lions squad after the Northampton hooker received an 11-week ban for abusing referee Wayne Barnes.
Hartley was sent off for allegedly calling Barnes a "cheat" just before half-time in Leicester's 37-17 victory over Northampton in the Aviva Premiership final at Twickenham.
A Rugby Football Union disciplinary committee rejected his version of events in which he claimed the abuse was aimed at Leicester counterpart Tom Youngs.
Hartley does though have the right of appeal but in the meantime Ireland hooker Best has been called up to join the squad which flies out to Hong Kong on Monday.
The head of the RFU's panel, Judge Jeff Blackett, said: "We cannot get around the fact that Wayne Barnes was certain that Mr. Hartley's comments were directed at him.
"Wayne Barnes said that if he had had any doubt in his mind, then he would have given the player the benefit of the doubt.
"In terms of sanction, calling a referee a cheat is an attack on his integrity and contrary to the core values of rugby and therefore we have taken a serious view and provided a serious sanction."
"At the hearing he pleaded not guilty but the panel found him guilty and determined that this was mid-range on the scale of seriousness."
"In accordance with the Lion tour agreement the six-week tour of Australia represents eight of the eleven weeks suspension because of the tour schedule. The remaining three weeks of the suspension cover three of Northampton Saints' pre-season matches."
Lions manager Andy Irvine said: "With uncertainty over the availability of Dylan Hartley to tour, and with the first of 10 matches only days away, we had no option but to call up the additional player.
"Despite the circumstances we should congratulate Rory Best, who will join the squad on Monday and fly with us to Hong Kong.
"A final decision on whether Dylan Hartley will take any part in the tour will depend on the outcome of any potential appeal."
Northampton are understood to be waiting until they receive the full written judgement from Judge Blackett before deciding whether or not to appeal.
The 11-week ban for Dylan Hartley was...?
Spot on - no place for that stuff in the game
Harsh - losing the AP final was tough enough