MIAMI GARDENS, Fla. -- Miami Dolphins rookie quarterback Tua Tagovailoa is expected to return to the starting lineup Sunday vs. the Cincinnati Bengals, sources told ESPN.

The Dolphins have been secretive of their quarterback plans all week, but they've been happy with Tagovailoa's progress from his left thumb injury that forced him to miss last week's win over the New York Jets, sources said. Dolphins coach Brian Flores has made it clear that "if he's healthy, he's the guy."

Tagovailoa has been wearing a black spica splint in practice this week to provide support to the base of his thumb while allowing mobility to the rest of his fingers. It's unclear yet whether he will be wearing the splint or any other support on the thumb during the game. Tagovailoa said earlier this week that he's "feeling good" and wants to play, but he deferred to Flores and the training staff.

It will be Tagovailoa's first action since being benched in the fourth quarter of the Dolphins' 20-13 loss to the Denver Broncos in Week 11 due to offensive struggles, and he has been eager for a bounce-back opportunity. It was his lone loss as a starter after winning his first three games. Tagovailoa and the Dolphins' offense will also receive a boost with running back Myles Gaskin returning to the starting lineup after missing the last four games with a knee sprain.

Tagovailoa suffered the injury after hitting a teammate's helmet while following through on a pass attempt in practice Nov. 25. Tagovailoa has participated in every practice since in a limited capacity, and he took significant reps with the starters this week in practice.

Wide receiver Jakeem Grant said Wednesday that "[Tua] looked great. ... He looked exactly the same. He picked up where he left off."

It's an important game for the 7-4 Dolphins, who need to keep pace with the AFC East-leading Buffalo Bills (8-3) and several AFC teams they are competing with for a wild-card spot. The Dolphins have a difficult end-of-season schedule, with four games against teams in playoff contention, including the Kansas City Chiefs next week.