Foster, who joined the Dolphins during the offseason and is coming off an Achilles injury, had his most extensive playing time with his new team in the third preseason game that was played at Orlando's Camping World Stadium.
Foster didn't get a lot more work, but he did enough in the seven touches he received to make the Dolphins' running back competition interesting. Ajayi carried seven times for 11 yards and caught two passes for 12 yards.
He completed 20 of 29 passes for 155 yards while leading the Dolphins to a score in one of two red zone opportunities.
Last week against the Cowboys, Tannehill led the offense to scores in two of three trips into the red zone.
Suh left the game with an ankle injury during the first half.
Copyright 2016 by The Associated Press