How an Uncommon Rule Led to Graham Glasgow’s Unexpected Shift to Left Tackle

An injury-driven moment on the Lions’ sideline showcases the intricacies of NFL rules.

A Surprising Lineup Change Amid Injuries

The Detroit Lions encountered a series of injuries during their game against the Indianapolis Colts on Sunday, including a concerning moment for left tackle Taylor Decker. Decker suffered knee and ankle injuries after being rolled up on during a Jared Goff sack. While he returned after missing a series, the play immediately following his exit caused a stir.

In a highly unusual sight, left guard Graham Glasgow slid to left tackle for a single snap. Michael Niese stepped in at left guard, only for Dan Skipper to replace Glasgow at left tackle on the subsequent play. Glasgow, a versatile player, later admitted that this was likely his first-ever snap at left tackle. Offensive coordinator Ben Johnson minimized risks by calling a quick screen pass to running back Jahmyr Gibbs for that specific play.

Decoding the NFL Rule Behind the Move

The reason for this momentary shuffle lies in a lesser-known NFL regulation. When questioned postgame, Glasgow shed light on the decision-making process.

“Skip reported as eligible the play before, so you can’t come in the next snap as an ineligible player unless you call a timeout,” Glasgow explained. “I don’t even know what was happening. They were just yelling on the sidelines and they just said, ‘Play left tackle for a play.’”

The incident ties back to Rule 5, Section 3, Article 2 of the NFL rulebook. This rule stipulates that a player who switches their eligibility status—such as reporting as an eligible receiver—cannot revert to their original position unless certain criteria are met. These criteria include events like a timeout, a foul, or the end of a quarter. Crucially, an injury timeout does not fall under these circumstances, creating a dilemma for the Lions’ coaching staff.

Avoiding a Penalty with Precision

In the absence of an eligible substitution, someone on the Lions’ sideline spotted the rule’s implications and acted quickly. By inserting Glasgow as a temporary left tackle, the team avoided a costly five-yard penalty for illegal substitution or the need to use a timeout.

The attention to detail demonstrated by the Lions’ staff reflects a deep understanding of NFL rules and situational awareness. While Glasgow’s stint at left tackle lasted just one play, it showcased how a team’s ability to adapt on the fly can preserve momentum during critical moments.

Fortunately for the Lions, Taylor Decker’s return indicated that his injuries were not severe, providing optimism as they prepare for a short week. Meanwhile, the brief shuffle on the offensive line serves as a reminder of the nuanced regulations that govern the game—and how even obscure rules can influence on-field decisions.

By leaning on Glasgow’s versatility and quick thinking from the coaching staff, the Lions turned a potential setback into a minor footnote, showcasing resilience in the face of adversity.