Stuart Lancaster has delayed naming his team due to a number of injury concerns, including Northampton scrum-half Lee Dickson who requires shoulder surgery and has been ruled out of this weekend's game and the forthcoming Churchill Cup.
Lancaster said: "We've got a couple of other injuries to assess and we'll have a look at some potential replacements in training today against the England Under-20 side.
"Another 24 hours will give us time to finalise the squad before we move to Pennyhill Park and train at Twickenham on Friday.
"Our preparations have gone well overall and we're pleased to announce that Luke Narraway will captain the side, which is a great reflection of the form and leadership qualities he's demonstrated at Gloucester this season."
Saracens-bound fly-half Charlie Hodgson is likely to start in a back division set to include capped internationals Matt Banahan, Ugo Monye and James Simpson-Daniel.
The Barbarians will announce their team later on Wednesday.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
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Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
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The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.