San Francisco 49ers

Sources: Alex Boone unhappy with contract

Alex Boone, who made a nearly seamless transition from tackle to guard two years ago, is unhappy with his contract and may not be part of the 49ers' Organized Team Activities that began today, sources said. Boone went undrafted in 2009. He signed a four-year extension in 2011, and he has two more years on the deal. ***UPDATE*** Boone was not on hand for today’s OTA session, the first of the spring for the 49ers.

The 49ers have an unusual situation on the offensive line in that their top player there, left tackle Joe Staley, signed a long extension early in his career and is making only a modest salary – $2.7 million in base pay – this season. Therefore it's difficult to pay other worthy linemen like Boone and fellow starting guard Mike Iupati, more than the left tackle. (The team already hiked up right tackle Anthony Davis' salary in the offseason).

Furthermore, the 49ers are working on a contract extension for Colin Kaepernick, one that promises to make him, by far, the highest-paid 49er and one of the highest paid players in the league. The 49ers, meanwhile, have routinely used mid-round draft picks on interior offensive linemen in recent years, including third-round picks on center/guard Marcus Martin and guard/tackle Brandon Thomas earlier this month.

Boone is scheduled to earn $2 million in base pay and count $2.6 million against the salary cap. Of the 49ers' projected offensive line starters, only center Daniel Kilgore will earn less.

The upcoming OTA sessions are voluntary, and it would not be abnormal for any veteran, including Boone, to skip the session. The first mandatory practices of the offseason are June 17-19 when the 49ers hold a minicamp.

Boone is represented by Jonathan Feinsod and Neil Schwartz. Several of their clients, from Darrelle Revis to Vincent Jackson to Roddy White, have held out for better contracts in recent years. Feinsod had no comment on a potential holdout by Boone when reached today.

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