Dallas will be without All-Pro guard Tyler Smith for at least four games after thumb surgery, forcing T.J. Bass into a major early-season role.

FRISCO – The Dallas Cowboys offensive line took a major hit before the 2026 season opener.

All-Pro left guard Tyler Smith will undergo surgery on his left thumb and is expected to miss at least four games, with Dallas placing him on injured reserve with a designation to return. The team currently expects Smith to miss roughly four to six weeks.

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That immediately puts T.J. Bass into the starting lineup at left guard.

Smith had tried to work through the injury, but the combination of pain, grip strength and the demands of playing offensive line ultimately made surgery the preferred option. For a player who relies on hand placement and power on nearly every snap, trying to gut it out carried too much risk.

Head coach Brian Schottenheimer made it clear the Cowboys believe Smith made the right call.

“He’s such a tough guy,” Schottenheimer said. “At the end of the day, we can’t pinpoint when it happened. It’s just one of those deals.”

Smith, 25, has already built one of the strongest starts to a career by an interior lineman in franchise history. He has made the Pro Bowl in each of the last three seasons, joining Larry Allen and Zack Martin as the only Cowboys guards to reach three Pro Bowls in their first four years.

His absence won’t be easy to replace.

Dallas will turn to Bass, who has 10 career starts over his first three NFL seasons and started five games in 2025. The Cowboys showed how much they valued him this offseason by placing a second-round restricted free-agent tender on him.

Schottenheimer said that confidence hasn’t changed.

“We feel really confident in T.J.,” he said. “He’s put great film on here.”

Bass also has familiarity working next to center Cooper Beebe and left tackle Tyler Guyton, which should help reduce the communication issues that often come with a sudden offensive-line change.

The larger concern is timing.

Smith’s earliest possible return would come after the mandatory four-game injured-reserve window, but Dallas won’t rush him back simply because he becomes eligible.

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That makes Bass one of the most important players on the roster to open the season.

The Cowboys built their offensive line around stability and strength inside.

Now, before the season even gets rolling, that depth is already being tested.