Andy Farrell completed his first England training session but only six of the 18 backs named in the senior squad on August 1 were available.
Robinson boosted numbers by handing opportunities to Wasps Academy and England Under-19 fly-half Dan Cipriani and Under-21 intentional full-back Nick Abendanon.
Cipriani, who starred in Wasps' Middlesex Sevens triumph on the eve of the new season, was included in England's Intermediate Academy for this year, while Bath's Abendanon is in the core sevens squad.
They are joined at the camp by 11 members of the National Academy squad, including winger Tom Varndell who has just been loaned out from Leicester to Bedford.
Robinson said: "It's important that players from both the Senior and Intermediate National Academies are involved in these training camps.
"The contribution of the Senior National Academy players last week and this has been excellent and I am impressed by their attitude both on and off the pitch.
"They have stepped up to the mark and fitted in well and haven't been fazed by being involved at this level.
"Daniel is a player who has come through the RFU Academy system at London Wasps and is one of many young players we are closely monitoring.
"We have also called up Nick Abendanon from England's core sevens squad and we are keen to see him train this week."
Robinson is holding the second of three training camps at his old university to prepare England for their autumn Tests, starting against New Zealand on November 5, followed by Argentina and two clashes with South Africa.
England have lost their last five internationals and the new coaching team need every opportunity possible to nail down the preparations.
World Cup winner Jason Leonard explained recently that the biggest thing this England team lacks is cohesion.
But Robinson had just 17 of his elite squad fit last week and 23 on Monday. Among those are two scrum-halves in Peter Richards and Shaun Perry plus Farrell, who has played just 85 minutes of first team rugby union.