DAVIE, Fla. -- Quarterback Ryan Tannehill has been ruled out Sunday versus the Detroit Lions, and the NFL has opened an investigation into how the Miami Dolphins reported his shoulder injury, a source confirmed to ESPN.

Brock Osweiler, who threw for a career-high 380 yards in a 31-28 overtime victory over the Bears, will start for the second consecutive week. Dolphins coach Adam Gase said he's not sure whether Tannehill will be able to play at Houston on Oct. 25.

"Anything that has to do with pocket movement, footwork, things like that, he can do everything," Gase said Wednesday. "He just can't throw."

Tannehill participated in practice on a limited basis Wednesday. He worked on footwork and handed the football off with his right (throwing) arm, but he did not throw during the open viewing period. The Dolphins (4-2) plan to ensure he's healthy and ready to react to the stresses of throwing before putting him back out there, Gase said. Rest has been the recovery recommendation for Tannehill.

Osweiler said he feels ready.

"Getting reps with the first-team offense and building some relationships out there in practice is huge. It's very beneficial," Osweiler said.

Gase said Monday he was "not sure" whether Tannehill faces a long-term injury, but he said he has complete confidence that the 30-year-old quarterback will play again in 2018. When asked about Tannehill's situation, Gase quickly interjected, "Yes, he will be the starter" when he's healthy.

Regarding prominent players, particularly starting quarterbacks, the NFL routinely investigates injury reporting. The NFL will gather details of how Tannehill went from full practice participant last Wednesday and Thursday to limited participant/questionable on Friday to out on Sunday, and see whether Miami adhered to the league policy.

Tannehill was made a surprise scratch for Sunday's game versus Chicago. The Dolphins say his right shoulder injury got "progressively worse" throughout the week.

Gase said Monday he believes Tannehill injured his right shoulder during a Week 5 loss, on a fourth-quarter forced fumble by Cincinnati Bengals defensive end Carlos Dunlap. Tannehill's arm was hit awkwardly from behind before he completed his throwing motion, and he was on the ground for a few moments after the play.

The NFL policy says this about injury reporting: "The policy requires that teams provide credible, accurate and specific information about injured players to the league office, their opponents, local and national media, and the league's broadcast partners each week during the regular season and postseason. The reporting process is of paramount importance in maintaining the integrity of the game."

It also refers directly to the practice and game status reports, which must provide clubs and fans with an accurate description of a player's injury status/availability and how much he participated in practice during the week.

It says this specifically about game status reporting: "Teams must notify the league, their opponent, local and national media, and the league's broadcast partners of the status of their injured players by 4 p.m. ET the day before their next scheduled game."

The term "normal repetitions" applies to a player's participation in both individual drills and the team portion of practice. Consequently, a player who participates in less than 100 percent of his normal repetitions during either the individual or team portion of practice should be listed as "Limited Participation."

Tannehill was listed as a full participant Thursday despite Gase later saying Osweiler took some of his first-team reps. Tannehill was also listed as questionable up until game time, despite ESPN and other reports labeling him as more "doubtful" than questionable. These are two of the issues that will need to be answered by the Dolphins. It's worth noting that these investigations regularly result in no penalty if the NFL is satisfied with the answers it receives.

The Miami Herald was the first to report the NFL's investigation.