Offensive tackle Tyron Smith has signed an eight-year extension with the Dallas Cowboys, through to 2023.

The length of the contract means that its total value is worth well over $100m (£59.1m) to Smith, whom the Cowboys see as a vital cog for their future.

Smith has already proved himself during his three years in Dallas so far, having started all but one match since joining the franchise. He was moved to left tackle during the 2012 season, where he has prospered.

The new deal includes $40m (£23.7m) guaranteed and a $10m (£5.9m) signing bonus.

Before signing the extension, Smith was already tied down to the franchise for a further two years.