Stefon Diggs is a father of six children in 2026 (Getty Images)For exactly three days, everything about the Washington Commanders' offseason made sense. They'd landed a genuine No. 2 receiver, Jayden Daniels finally had real weapons around him, and the vibes across training camp were as good as they'd been all summer. Then Saturday practice happened, and the whole storyline flipped.Stefon Diggs gave the Commanders hope; Laremy Tunsil's triceps took it away.Diggs' free agency saga had dragged for months. The Patriots released him in March purely for cap relief, even though he'd just led their receiving corps to a Super Bowl appearance. Washington waited him out, and on August 5, it paid off.Diggs signed a one-year deal worth up to $12 million, and the team made it official two days later. For a guy from Gaithersburg, Maryland, it was framed as him coming home, and for the Commanders, it was framed as exactly the piece missing next to Terry McLaurin.Behind those two, the depth chart had been thin: Treylon Burks, Luke McCaffrey, a rookie. Diggs instantly became the best receiver not named McLaurin on the roster, and gave Daniels a second real threat defenses actually had to respect.For a team that went 12-5 with an NFC Championship run in 2024, then collapsed to 5-12 in 2025 largely because of injuries, the Diggs deal read like exactly the kind of aggressive, no-nonsense move that had defined Washington's whole offseason approach. Add it to trading for left tackle Laremy Tunsil back in March 2025, and this looked like a front office building something real.The low: Tunsil goes down, and it's not minorThen Saturday came. During a one-on-one pass rush rep against Odafe Oweh, Tunsil tried to stop a bull rush, the two locked up, and Tunsil awkwardly disengaged, immediately grabbing his arm in obvious pain.The diagnosis: a torn triceps. He'll need surgery, and the recovery window for that injury typically runs four to seven months, meaning Washington's best offensive lineman, a five-time Pro Bowler who'd just become the NFL's first $30-million-a-year tackle five months earlier, is likely out for most, if not all, of the 2026 season.The timing is almost cruel. Tunsil was PFF's sixth-ranked tackle in the league last year, allowing just two sacks and 15 pressures the entire season. He was the only Commander named to ESPN's top-10 players survey heading into this year. And he was supposed to be the guy keeping Daniels upright after a 2025 season where Daniels himself missed 10 games to three separate injuries.A team that can't seem to get a full deckWashington's internal options to replace him aren't great. Andrew Wylie has played almost exclusively right tackle for his whole career. Brandon Coleman, who'd been competing for a starting guard spot, is the most likely candidate to slide out to tackle; he started 12 games there back in 2024, so it's not unfamiliar territory, but it's also not Tunsil.So here's where the Commanders sit: a receiving corps that looks genuinely dangerous for the first time in years, and an offensive line that just lost its best piece before the season's even started. One signing bought them a week of optimism. One practice rep took it right back.