The San Francisco 49ers had safety Julian Blackmon in the building for a visit last month and let him leave without a contract.

Now their hopes of signing one of the top safeties still on the open market has gone after Blackmon re-signed with the Colts on a one-year deal, per Jordan Schultz of Bleacher Report.

Blackmon is coming off a career year in 2023, which saw him record eight pass breakups, four interceptions and five tackles for loss, all of which were career-high tallies.

His passer rating against of 28.8 was the best in the NFL among safeties with at least 20 targets last season, per Sports Info Solutions, which rated Blackmon as the fifth-best safety in the NFL by Expected Points Added allowed per target.

Still only 25, Blackmon seemingly still has the best years of his career ahead of him. A dormant safety market gave the 49ers to snap him up and fortify their depth at a position where they don't have any convincing options beyond their starters.

Ji'Ayir Brown is coming off a hugely encouraging rookie year that ended with an interception in the 49ers' Super Bowl 58 defeat, but he only played in five regular-season games in 2023. Talanoa Hufanga, an All-Pro in 2022, is coming off a torn ACL suffered in Week 11 last year.

As such, stellar play at the position is far from a certainty, and the 49ers would be in a difficult spot were either player to suffer an injury.

Patience not always a virtue

Per David Lombardi of The Athletic, the 49ers told Blackmon he would not be guaranteed a starting role when they had him in town for his visit.

While they were right to be honest with Blackmon, not making a more concerted effort to add him and find a role in which he would be satisfied could prove to be a mistake by the 49ers.

As general manager John Lynch indicated at the annual league meetings, the 49ers are in a position where they can be patient in adding to their depth at safety with the likes of Justin Simmons, Quandre Diggs and Micah Hyde still on the open market.

But they had the opportunity to sign an ascending talent at an underrated position of need and minimize the impact of Hufanga or Brown struggling or suffering an injury.

Given how long he stayed on the market, league opinion of Blackmon may not be reflective of his hugely impressive numbers. Still, chances to sign a young player coming off a career season to what likely would have been a cheap contract do not come around very often.

The merits of veterans like Simmons and Diggs are not in question but, in contrast to Blackmon, they are on the downswing of the career. Signing Blackmon would have given the 49ers three players all aged 26 or under at a position that is consistently undervalued by the league.

All their eggs in one basket

San Francisco's scope for mixing up its coverage looks would have been greatly increased with a safety of Blackmon's ability in their defensive backfield and, going into a contract year for Hufanga, could have expanded the menu of options for the 49ers at the position next offseason.

Instead, they at least for now appear to putting all their eggs in one basket and hoping that Brown and Hufanga stay healthy and deliver on their obvious promise as a safety pairing, making it an easy decision to extend their 2021 fifth-round pick.

There's plenty of reason to believe their faith will be vindicated, but it's also a risk the Niners didn't necessarily need to take. They would have had the option of extending Hufanga regardless, but signing Blackmon would have given them another potential long-term avenue if he proved himself the more viable starter in 2024.

Sometimes it's the moves you don't make, and it's fair to wonder if the 49ers will eventually come to regret not keeping Blackmon in the building and signing a player whose arrival would have immediately removed all nerves about their safety depth.

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He should still have something in the tank.