Brad Barritt is a doubt for England's clash with France on Saturday as centre continues to provide head coach Stuart Lancaster with the most challenging conundrum in selection.
Barritt is struggling with a tight calf and may miss the trip to Paris in the second of two World Cup warm-up matches against Les Bleus, who were toppled 19-14 at Twickenham last weekend. Lancaster names his team on Tuesday evening and will recall a raft of first-team regulars such as Dan Cole, George Ford and Mike Brown, but the make-up of the midfield is yet to be decided.
The performances of debutants Sam Burgess and Henry Slade against France have increased the options and ideally they would start in Paris, but Lancaster is mindful of the need to offer Luther Burrell and Billy Twelvetrees the chance to advance their claims to a place in the World Cup squad and give game time to Jonathan Joseph and Barritt, if fit.
Barritt, who Lancaster described as "not definitely" available for Saturday, and Joseph are the only certainties to make the World Cup with Burrell, Twelvetrees, Burgess and Slade fighting it out for the remaining two available spots.
"It would be nice to have a few more warm-up games before we make the decision but we don't," Lancaster said. "Selection will be difficult in that regard because I'm aware other guys need to play as well. It's that position in particular that is taking up most of the time in selection.
"There are centres others than Burgess and Slade who we need to consider as well - there are three centres who haven't played. Getting that balance right of who plays in this particular game will lead into final selection for the World Cup."
Tighthead prop Kieran Brookes suffered only a bruised hand against France on Saturday and is able to train, but loosehead Alex Corbisiero has sciatic nerve pain and is a doubt. Number eight Ben Morgan came through unscathed after negotiating 40 minutes at Twickenham in his first appearance since breaking his leg in January, but England continue to monitor him closely.
Billy Vunipola will come into the back row at the Stade de France and Lancaster must decide whether Morgan is ready for another outing from the bench, given he has only just returned to full fitness.
"Ben came through fine. He's a bit sore but no more than you would expect. We will see how he goes during the course of the week as to whether we use him this weekend," Lancaster said. "It was a big step for him to go out and play 40 minutes at international level having not played for eight months, so we'll make a decision at the end of the week. He will be available but I'm not so sure he'll be used this week."
Apart from inside centre and one wing position, Lancaster is set to name his strongest starting XV against France before the visit of Ireland to Twickenham on September 5 completes England's trio of warm-up fixtures.