It will be Warburton's first Lions tour, but Gatland likes his character, being especially impressed with his reaction to adversity during the recent Six Nations, and his naturalon-field leadership qualities. Warburton is also comfortable with the media.
His appointment sets the tone for a party that will be dominated by Welshmen and could feature as few as eight English players.
With Gatland set to take Wales' Justin Tipuric and Ireland's Sean O'Brien alongside Warburton as openside flankers, Robshaw may not make the tour party at all.
The England captain could play at blindside flanker, where his teammate Tom Croft is a likely tourist, but his fate could be sealed by the final decision last night on Wales' Dan Lydiate.
There are some concerns about Lydiate's match fitness after he broke an ankle in early season. Lydiate, O'Connell and Ireland wing Tommy Bowe are three players Gatland has been eager to return to fitness after long lay-offs.
There will be few surprises, but it is possible that there will be a bolter in Billy Twelvetrees, who started just twice for England during the Six Nations, and could be selected as an inside centre.