Arsenal midfielder Oxlade-Chamberlain has not played since April 20 due to a groin injury, while versatile Manchester United defender Phil Jones has been plagued by a shoulder problem.
Neither player was involved in England's first warm-up friendly ahead of the FIFA World Cup, against Peru on Friday, but the duo are in line to feature against Reinaldo Rueda's men.
"They will both play from the start," England manager Roy Hodgson revealed. "They could have both played against Peru, but we thought an extra day's training would do them more good than being on the bench."
Hodgson is planning to give run-outs to the players that did not start the 3-0 win over Peru at Wembley, with Everton full-back Leighton Baines almost certain to be rested as he nurses a groin strain, though the injury is not thought to be serious.
Southampton's Luke Shaw is set to get the nod in Baines' place, the highly-rated 18-year-old having shook off a cold that prevented him from facing Peru.
"Our plan really on Wednesday is basically to start the people who didn't start on Friday," Hodgson added. "But plans like that sometimes go astray and I'm not prepared to make any promises."
England will take on Ecuador and Honduras in Miami, where Hodgson's men - who face Italy in their World Cup opener on June 14 - are completing final preparations before travelling to Brazil.
Hodgson said: "Wednesday will be an opportunity for me to start the others and then by Saturday (when England face Honduras) we've got all of them having played and ready to play. And then I'll have to make a decision over who does play against Italy."
For Ecuador, the meeting with England provides a last opportunity to get valuable game time before they meet Switzerland on June 15.
Rueda will be keen for his team to improve on the showing they delivered in a 3-1 defeat to Mexico in Texas on Saturday.
That match was marred by Mexico's Luis Montes suffering a broken leg that rules him out of the World Cup.
Montes was injured in a challenge with Ecuador's Segundo Castillo, who faces a nervy wait to discover if he will be able to participate in Brazil after hyper-extending his knee in the collision.
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