A first-round pick of the 49ers in 2010 (No. 17 overall), Iupati was a mainstay at left guard as he was selected to three Pro Bowls and was named All Pro once.
But injury and ineffectiveness slowed him in 2014, when he missed a game with a concussion and sat out the Pro Bowl with an elbow injury. Plus, the Niners going away from the power-running game and more to a spread passing attack did not play to Iupati's strengths.
Iupati, 27, was non-committal about returning to San Francisco and, according to Pro Football Focus, he finished 14th out of 78 guards with an overall grade of plus-11.2, though his minus-18.5 run blocking grade was second and his plus-7.5 pass blocking grade was 55th.
ESPN.com 49ers reporter Paul Gutierrez contributed to this report.