Neither Bolton's Sordell nor Blackpool's on-loan Aston Villa striker Delfouneso have featured since the European Championship play-off with Serbia in October.
But both will have the chance to impress as part of a 26-man squad to take on Romania U21s and Austria U21s in the last two friendlies before Pearce names his squad for this summer's Israel tournament.
Jack Butland drops back down from senior duty following Ben Foster's decision to come out of international retirement, joining fellow full internationals Steven Caulker, Jordan Henderson, Jonjo Shelvey, Raheem Sterling and Wilfried Zaha in the squad.
And Caulker's Tottenham club-mates Tom Carroll, Andros Townsend and Danny Rose are all included.
Pearce said: "We are now moving into our final preparations for what we hope will be a prosperous summer. Next week is an important opportunity for the players to impress as they look to secure a seat on the plane."
England U21s tackle Romania U21s at Wycombe on 21 March before moving on to Brighton to take on Austria U21s four days later.
Squad: Amos, Butland, Rudd, Steele, Bennett, Caulker, Clyne, Dawson, Lees, Robinson, Rose, Shaw, Smith, Wisdom, Carroll, Chalobah, Henderson, Lansbury, Lowe, McEachran, Shelvey, Sterling, Townsend, Delfouneso, Ince, Sordell, Wickham, Zaha.