The 23-year-old was left out of Chelsea's squad for their opening two league matches and was an unused substitute for the League Cup second-round tie against Luton, having only recently returned from a hamstring injury sustained in late July that kept him out for close to three weeks.
According to The Athletic, Chelsea had also placed Emegha on a list of players available for transfer over the summer, alongside the likes of Marc Guiu, Liam Delap, Nicolas Jackson and João Pedro, though he has remained at Stamford Bridge.
Asked about the situation, Alonso said his young forward would need to wait his turn.
"He is young, he has particular qualities," the Chelsea manager said in a press conference. "We hope he feels better and does what's needed to get more involved.
"Young players have to show patience, but they will get their chance."
Emegha will not be involved when Chelsea travel to face Arsenal in a significant Premier League fixture, with Alonso instead expected to turn to alternatives up front.
The Netherlands international had joined Chelsea from Strasbourg for around €26m in 2025 before spending a season back on loan in Alsace, where he scored 31 goals and provided seven assists in 78 appearances across his time with the Ligue 1 club.
He left France not unhappy to end a fractious relationship with Strasbourg's supporters, who had jeered him after his move to Chelsea was announced and clashed with him on more than one occasion, including after he wore a Chelsea shirt following a match against Rennes.
His arrival in London was further complicated when he missed out on the 2026 World Cup, with Netherlands manager Ronald Koeman leaving him out of his squad due to fitness concerns.
Emegha did score on his Chelsea debut in a behind-closed-doors friendly against Crawley, but has not featured for Alonso's side in an official fixture since his move, leaving him to watch on as his new club's transfer business and injury list continue to shape the pecking order ahead of him.