Robson follows in the footsteps of club-mate Chris Robshaw, who led England in the first test against South Africa last weekend in Durban.
“George has had a tremendous season for Harlequins, has made a great contribution to this tour already, both in training and as part of the leadership group, and I know he will captain the team well,” Lancaster said.
The team to play the Southern Barbarians is a completely new one, with the whole England squad, save for wing Ugo Monye and prop Alex Corbisiero, getting game time in the first two matches of the tour.
England lost the first test 17-22 to the Springboks and Lancaster said he hoped the midweek team would help the squad to bounce back from that disappointment.
“Every one of the 22 is desperate to play. They have trained superbly and their attitude while waiting for their chance has been first-class. There is a lot of competition for places across the board and Wednesday gives these players a chance to lay down a marker and for the whole squad to build some momentum towards Saturday’s test. We need to make sure we get back on track,” Lancaster said.
The England coach admitted, however, that it was unlikely anyone playing in Wednesday’s match would come through and make the starting XV for the second test in Johannesburg on Saturday.
“We’re close to being finalised for the team for Saturday, but we are still looking at one or two players, although they are more likely to be on the bench for Saturday,” Lancaster told a news conference in Johannesburg on Monday.
With experienced players such as halfbacks Charlie Hodgson (38 test caps) and Danny Care (32 caps) and flank James Haskell (42 caps) in the midweek team, Lancaster said he was excited by the match.
“I’m really looking forward to the game. From the players’ point of view, obviously they’re just desperate to get out on the park, but for me it’s an opportunity to build a squad and work with the players. There’s nothing better for a coach than to coach players in a game situation,” Lancaster said.
The former England Saxons head coach said he was playing two inside centres – Anthony Allen and Jordan Turner-Hall – in midfield on Wednesday because he wanted to develop England’s depth at outside centre.
“I’m playing what would be regarded as two specialist 12s because I want to look at Anthony Allen at 13. I want options for England there and Anthony played outside Brad Barritt in the Churchill Cup.
“The plan is that he will move to 12 in the second half and George Lowe will come on at outside centre. It’s about creating opportunities for everyone and not pigeonholing them,” Lancaster said.
The midweek team’s starting line-up includes seven players who have not yet played test rugby for England – fullback Alex Goode, wing Christian Wade, hooker Joe Gray, locks Graham Kitchener and Robson, flank Carl Fearns and New Zealand-born eighthman Thomas Waldrom.
Team – 15-Alex Goode, 14-David Strettle, 13-Anthony Allen, 12-Jordan Turner-Hall, 11-Christian Wade, 10-Charlie Hodgson, 9-Danny Care. 8-Thomas Waldrom, 7-Carl Fearns, 6-James Haskell, 5-George Robson, 4-Graham Kitchener, 3-Paul Doran-Jones, 2-Joe Gray, 1-Mutt Mullan. Replacements: 16-Tom Youngs, 17-Rupert Harden, 18-Tom Palmer, 19-Jamie Gibson, 20-Lee Dickson, 21-George Lowe, 22-Nick Abendanon.