JOHANNESBURG (AFP) - The British and Irish Lions suffered a major setback ahead of the third and final Test against South Africa on Saturday when Ireland captain Brian O'Driscoll was ruled out with concussion.

O'Driscoll, 30, suffered a clash of heads with replacement Springbok Danie Rossouw late on in the second Test last weekend, won 28-25 by the home side for an unassailable 2-0 series win, and will travel home on Wednesday.

Also heading home will be Ospreys and Wales prop Adam Jones, who suffered a dislocated shoulder after an illegal Bakkies Botha charge during the match requiring hospital treatment to have the shoulder put back into place.

O'Driscoll, who was badly concussed, began the return to play medical protocol on Monday. However, it soon became clear at the start of the process that he was not going to be ready for a return to action for Saturday's third Test at Ellis Park here.

O'Driscoll, who has won 93 caps for Ireland and six Lions caps, suffered simmilar injury woes on the last Lions tour to New Zealand four years ago, when a spear-tackle in the opening minutes of the first Test saw him dislocate a shoulder.

"Being a part of the 2009 British and Irish Lions squad has been one of the highlights of my career," said the Leinster centre.

"We were unbeaten leading into the Test matches and it is a shame that the results in the Tests did not go our way but sport comes down to fine margins at times.

"We could easily have won the first two Tests but it wasn't to be. I have decided to return home to my family this week after a very long season and to ensure I give myself every opportunity to recuperate."

Jones will return home for further specialist opinion and treatment on his injured shoulder.

"It is always disappointing to be ruled out of a Test series through injury but I am proud of what the squad and I have achieved on the tour," Jones said.

"Personally I will always remember playing in the two first Tests and especially running on for my debut in the starting XV at Loftus Versfeld."

Prop Gethin Jenkins suffered a broken cheekbone in the same match and was also ruled out of the rest of the tour but will stay with the tour party.

Springboks assistant coach Dick Muir said the Lions would miss O'Driscoll, whose centre partnership with Jamie Roberts has thrived in South Africa, in the Ellis Park clash on Saturday.

"O'Driscoll is a class act, who has shown what he's all about in the Test series," Muir said. "He caused us to tighten up our defences."

Muir added that he did not think that the Lions would be radically changing their gameplan come Saturday.

"They have an astute coaching team and I'm sure they won't tweak too much with their game.

"They are a very good Lions side and we've had two games that could easily have gone either way.

"It's been down to the wire in both Tests and I was also involved (as coach) with the Emerging Springboks" during last week's 13-13 draw with the visitors, said Muir.

"We know it's going to be tough, and a very tight contest."