Donald Brown joins crowded San Diego Chargers backfield

(Michael Hickey/Getty Images) As much of the attention fell on Trent Richardson and, to a lesser extent, Ahmad Bradshaw in Indianapolis last season, Donald

(Michael Hickey/Getty Images)

As much of the attention fell on Trent Richardson and, to a lesser extent, Ahmad Bradshaw in Indianapolis last season, Donald Brown excelled under the radar. He traded in one jumbled depth chart for another Tuesday, signing a deal with the San Diego Chargers. Bill Johnston, the team's director of public relations, confirmed on Twitter that Brown had received a three-year contract.

Chargers agree to 3-yr contract with RB Donald Brown, former first-round pick of Colts.

— Bill Johnston (@BillJohnstonNow) March 12, 2014

Brown finished last season with 102 carries and 27 receptions for the Colts, both numbers below those of Richardson. That's despite the fact that Brown was far more effective than Richardson on the ground -- Brown averaged 5.3 yards per carry and scored six TDs; Richardson posted a puny 2.9 per-carry mark with three scores.

So, where does Brown fit in San Diego? Well ... good question.

The Chargers have both Ryan Mathews and Danny Woodhead under contract for another season. Together, they combined for nearly 2,500 yards from scrimmage last season, with Mathews playing a full 16-game schedule for the first time in his career. However, the run game hit the wall in the playoffs as Mathews dealt with a high-ankle sprain.

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That struggle may have been enough to convince the Chargers to add another body in the backfield, as Woodhead is a better fit as a change-of-pace back (76 receptions last season) than an every-down force. Brown has never accumulated more than 134 rushing attempts in any of his five NFL seasons to date, but he should be able to step in alongside Woodhead should Mathews revert to his injury-plagued ways.

San Diego also could save $1.5 million toward the salary cap by releasing Woodhead, though it's hard to imagine that happening after his strong 2013 season.

The answer to Brown's role then: Ask again later.

Grade: C-minus. This might be a long con type of signing -- with Brown now locked up for multiple years, at least one of the Mathews-Woodhead pairing probably will be gone by the 2015 season. Right now, the move feels a bit like overkill at a position where players have been increasingly attainable via the draft or later in free agency.