Dominic Calvert-Lewin was forced off in the second half with a hamstring injury. The striked missed the opening nine matches of the season with a knee problem.
Amadou Onana also came off at the same time as Calvert-Lewin, having sustained an ankle complaint.
And Idrissa Gana Gueye was forced off at half-time with a quad problem.
All three will undergo scans on Sunday as Everton await further information.
Everton manager Lampard said: “Gana is the top of his squad sensation, scan on Monday. Dominic is a hamstring, scan on Monday. Onana is an ankle, scan on Monday.”