The exciting forward, signed from Brentford, was not part of the squad for the 2-1 victory over West Ham United in New Jersey.
As he builds his fitness, being behind the rest of the group in that respect, Mbeumo is set to also miss our next Premier League Summer Series game, against Bournemouth, in Chicago.
However, Amorim hopes he can hand the Cameroon international his bow in next weekend's clash with Everton in Atlanta.
"Bryan is starting slowly," said Amorim. "He is not going to play in the next one.
"We hope to have Bryan in the last game [in the United States].