By Chad Finn, Boston.com Staff

He will forever be associated with the San Diego Chargers for reasons both triumphant and tragic. But the coda to Junior Seau's brilliant 20-year NFL career came here in New England, where he spent 38 regular-season games over four seasons proving how a player of such individual distinction could become a wonderfully enthusiastic role player and teammate.

Seau, who died Wednesday from an apparent self-inflicted gunshot wound at age 43, was a favorite of the coach, Bill Belichick, who once coached Lawrence Taylor with the Giants and has an obvious affection for linebackers of extraordinary skill and ability. While Seau's greatest days came as a San Diego Charger, the franchise for which he made 12 Pro Bowl appearances in his 13 seasons, Patriots fans have their snapshots of him, too.

He is remembered foremost for his toughness. After suffering a gruesomely broken arm in a November 2006 game, he walked off the field saluting the fans (with his good wing), then returned the following season to play all 16 games.

He is remembered for his enthusiastic willingness to join the Patriots in the middle of a season when Belichick would call to tell him his services were needed. Once, he said the call came while he was on a surf board, enjoying his retirement that was about to prove temporary again.

And he is remembered, admiringly despite the outcome, for his words of encouragement to Tedy Bruschi -- "Get a stop. We've just got to get a stop'' -- as the defense prepared to take the field for the final time in Super Bowl XLII. His teammates seemed to want that ring for him as badly as they wanted one for themselves.

When we watched him in his Patriot years, it was impossible not to recall one glaring what-if that hovered over the franchise for years. Seau could have, and probably should have, been a Patriot so much sooner.

In the 1990 NFL Draft, the Pats owned the third overall selection, courtesy of a 5-11 record the previous season. Rather than keeping the coveted selection for themselves, the Patriots did what they did in those days -- they made a decision that would haunt them, trading out of the spot, giving Seattle the pick along with a second-rounder in exchange for two first-rounders (Nos. 8-10), and a third-rounder.

The Seahawks selected Cortez Kennedy, who was elected to the Pro Football Hall of Fame in February.

Two picks later, the Chargers chose Seau, who will be elected to the Pro Football Hall of Fame the first moment he is eligible for consideration.

And with the No. 8 pick, the Patriots, in dire need of linebacker help, chose ... Chris Singleton from Arizona. He played six years in the league, finishing with seven career sacks. He did not make the Pro Football Hall of Fame. The Patriots went 1-15 in 1990.

Patriots history would be changed beyond recognition if they'd chosen the right player that day. Maybe Seau gives them instant defensive credibility, and the franchise is never in position to draft Drew Bledsoe (No. 1 overall, 1993) or Seau's Southern Cal successor, Willie McGinest (No. 4 overall, '94). But even in a Patriot fan's lament, this much is certain: Seau ended up where he belonged.

He wasn't just a Charger, he was the Chargers, crackling with electricity every time the ball was snapped. Relentless, ferocious and impossibly athletic from his linebacker position, he was superb at every aspect of playing the position. His talent, knowledge and instincts were such that he got away with freelancing more than any linebacker who didn't answer to L.T.

Before coming to New England, Seau spent three years in Miami, and his first 13 of his 20 NFL seasons with the Chargers. He's arguably that franchise's all-time most beloved and iconic player. Wednesday, he became part of their tortured legacy, becoming the eighth member of their 1994 Super Bowl team to die.

As a Patriots fan, it was easy to envy the Chargers fans who were lucky enough to have watched Seau wreak havoc on opposing offenses every Sunday in his heyday. You wished he could have arrived in New England sooner than he did. But Monday, football fans everywhere were united in sadness, wondering why he had to go.

@GlobeChadFinn