England v South Africa LIVE from the Rose Bowl
Morgan revealed one change to his side as Jake Ball replaced a stricken all-rounder – but not the one anyone expected.
Ben Stokes only bowled two overs in Leeds and left the field with a knee problem but it was Chris Woakes who missed out with a niggle.
"The niggle that Stokes has had has been around a long time and he's managed it well," Morgan said.
"We went for Jake who takes the new ball and does well at the end for us as well."
AB de Villiers meanwhile confirmed three changes to his South Africa side at the toss, admitting they had not been at their best at Headingley but also that they wanted to ensure their whole squad got a game ahead of the Champions Trophy.
The skipper handed slow left-arm spinner Keshav Maharaj his One-Day International debut after taking 26 wickets in his first seven Test matches.
The 27-year-old came in for leg-spinner Imran Tahir while Farhaan Berhardien and Dwayne Pretorius replaced JP Duminy.
Morne Morkel will play at Lord's on Monday, De Villiers confirmed.