International coaches do not ditch emblematic players on a whim. Gatland and O'Driscoll have a strong history and Gatland has bridged a selection gap which many coaches fail to do.
He has removed any sentiment from his decision. He has ignored pleas to give O'Driscoll the chance of a farewell flourish with the Lions and picked the Welsh firm of Jamie Roberts and Jonathan Davies instead in midfield.
That partnership suits the concentration of Welsh players in Saturday's final test.
It is a combination which has been an invaluable platform for Wales in their rising international success. They are a proven duo who are very comfortable with the intricacies of each other's play where Roberts is the hammer and Davies is the sickle.
Roberts is a huge man who bends and can break defensive lines for Davies to take an offload or the forwards to rumble ahead. The other player in world rugby with similar power in that role is Ma'a Nonu.
Picking the Welsh pair is a decision with plenty of rationale but ignoring O'Driscoll for the reserves bench and preferring the heavyweight Manu Tuilagi, does not make as much sense. Not unless some of the in-house medical reports have had some influence on the decision.
Perhaps Roberts' right hamstring is a not quite right and with that liability and the unwavering final test commitment to play up the guts GattyBall, Tuilagi is a handy similar heavyweight replacement.
Teams are more potent if they can play a mix of styles and picking O'Driscoll on the bench would have given the Lions that variation in tandem with either Roberts or Davies.
His experience would also be invaluable in the white hot last 30 minutes of a series when the Lions are either looking to hold their lead or chase a deficit for an historic series victory. Tuilagi might have the ballast but he does not have that sort of savvy to call on.
