Joshua Garnett had a chance at returning to the 49ers this season after have knee surgery in August. But the team decided it would be better if the guard took the season off to re-shape his body to compete for a starting role in 2018.

Garnett wound up going on injured reserve before playing in a preseason game, washing out his second season after San Francisco traded up to select him 28th-overall in the 2016 NFL draft.

The 49ers will approach the coming offseason knowing they need to upgrade their play along the interior of the offensive line. Garnett will be given a shot at earning back his starting spot, general manager John Lynch said Tuesday, but he’ll have to make changes.

“We took a long term view with Josh. … So we made that decision, which was a hard one but we certainly hope that he responds well. He’s working his tail off. He’s done a great job of really changing his body composition,” he said.

Lynch and first-year coach Kyle Shanahan have made sweeping changes in their first seasons, which included asking some players to change their bodies.

Lynch said the club would use Garnett as a model for players that need to transform physically to fit the 49ers’ style of play. For Garnett, that means being more nimble to block for Shanahan’s outside zone rushing scheme after playing in a power-based attack at Stanford.

“We took a really holistic look and I challenged everybody on our medical and strength and conditioning to our functional performance guys to our nutrition and we challenged Josh with, ‘We want to do this and here’s why and we want you to use it as an opportunity to really improve yourself in every aspect.'” Lynch said.

For now, Laken Tomlinson, a 2015 first-round pick by Detroit, and Brandon Fusco are the starting guards with Daniel Kilgore at center. Tomlinson was acquired in a trade Aug. 31 and has another year remaining on his rookie contract. Fusco is slated for free agency in the spring, but has played well of late despite dealing with a debilitating biceps injury.