Sunday marked the one-year anniversary of Rick Spielman's bold but necessary trade for Sam Bradford in a Hail Mary attempt to save the Vikings' 2016 season after Teddy Bridgewater's devastating knee injury.

In the pecking order of Spielman's personnel decisions last season, nothing comes close to acquiring a starting quarterback at the cost of a first-round pick. His next three most important moves were signing free-agent guard Alex Boone and drafting receiver Laquon Treadwell in the first round and cornerback Mackensie Alexander in the second round.

Now fast-forward one year.

Spielman cut Boone on Saturday, leaving $3.4 million in dead money on the team's tab. Spielman also traded for veteran cornerback Tramaine Brock over the weekend, presumably as insurance because Alexander has yet to prove he can handle the nickel-corner job. In May, Spielman took a gamble on wide receiver Michael Floyd after Treadwell contributed next-to-nothing in his rookie season.

Those moves show that the Vikings general manager is feeling real pressure to deliver a winner this season and can't afford to sit patiently and hope that things improve.

The Vikings haven't won a playoff game since 2009. Their 2016 season became an epic unraveling. No doubt the Wilf ownership expects to see substantial improvement and signs that the organization is on a championship trajectory in a season that will end with the Super Bowl extravaganza being held in their new home.

This is a critical season for Spielman's operation, which puts those aforementioned moves into context.

Treadwell caught one pass in his first season. That doesn't mean he is doomed to be labeled a bust, but his disappearing act caused enough concern that Spielman sought outside help in signing Floyd, whose off-the-field problems made him available.

Boone's signing was celebrated at the time as a potential quick fix at one spot along a woeful offensive line. A year later, he's gone, largely because the Vikings changed coordinators and shifted to zone-blocking schemes, a bad fit for Boone's skill set.

Spielman probably swallowed hard in releasing Boone because the optics look bad — not to mention the financial hit incurred — in cutting ties with an expensive free agent after one season. But the Vikings offensive line looked better without Boone this preseason, a jarring realization. Spielman understands the ramifications of not solving a glaring hole in his roster after neglecting that position in previous drafts.

Spielman likely reflected on a hard lesson learned in trading for Brock. His decision to cut Antoine Winfield in 2013 and hand the slot/nickel job to unproven Josh Robinson proved disastrous. The defense never recovered.

Spielman didn't re-sign Captain Munnerlyn this offseason in part because he knew he had mega-contract extensions looming. The Vikings have committed $135 million in guaranteed money to four defensive stars: safety Harrison Smith, defensive end Everson Griffen, cornerback Xavier Rhodes and nose tackle Linval Joseph.

Those big-ticket costs caused Spielman to entrust Alexander to handle the nickel role, even though he lacked experience in that spot. Nothing to date suggests that Alexander can be trusted unequivocally with that responsibility.

The fact that Mike Zimmer played Alexander in the final preseason game while the rest of the defensive starters sat indicated the second-year corner needs more experience in learning the nuances of that position. Alexander didn't help himself by picking up a foolish taunting penalty after a third-down incompletion, which opened the door for Miami to score a touchdown.

Spielman traded for Brock the next day, hardly a coincidence.

The Vikings can't afford to sit and suffer if Alexander struggles as their nickel. They gave themselves insurance in Brock, who could replace Alexander if the experiment fails miserably. That would allow veteran cornerback Terence Newman to remain outside where he's more comfortable.

Spielman drafted Alexander in the second round because he believes in his talent. The organization is invested in his development. Same thing with Treadwell. Boone's contract gave the appearance of security.

But the clock is ticking on Spielman's hand-picked roster to ascend and distance itself from last season's debacle. That urgency was evident in recent personnel decisions.

Chip Scoggins • chip.scoggins@startribune.com