What's going on with Al Horford and Covid?

75756A5E-120A-4932-810C-2FD980DB785E

Ime Udoka says Al Horford is feeling fine, yet he was ineligible to play Tuesday against the Heat after winding up in the NBA’s Covid Health and Safety protocols.

What’s going on?

The NBA has altered its protocols multiple times over the last two years, with the latest guidelines being enacted in January, when the first Omicron surge driving up infections across the league. In an effort to keep players on the court, the NBA decided it would only test players and coaches for Covid if they were experiencing symptoms or recently exposed to an infected person.

Players who were unvaccinated or had not yet received their booster were still subject to daily testing, but only through Feb. 17.

It’s apparent Horford was placed into the Health and Safety protocols late Tuesday afternoon. He flew with the Celtics down to Miami and was even spotted at the team’s shoot-around Tuesday morning. Reports about Horford’s unavailability began to trickle out early in the 6:00 p.m. hour.

This is Horford’s third stint this season in the Health and Safety protocols.

There was recently speculation about the vaccination status of Celtics players after the Globe’s Gary Washburn had reported at least two of the team’s stars are unvaccinated. Washburn’s report followed a Celtics road game against the Raptors in which Jayson Tatum, Jaylen Brown and Horford were all on the injury list for ambiguous reasons.

Their absences were curious, because Canada mandates that all unvaccinated visitors spend 14 days in quarantine, which would’ve made it impossible for them to play if they weren't vaccinated. At the time, the Celtics were slated to face the Raptors in the NBA Playoffs.

When Udoka was asked about the issue March 29, he was indirect, but eventually said “all of our guys, if healthy, are available to play.” Two days later, Horford seemingly confirmed he was vaccinated.

“We're clear on it. And I'll be ready to play wherever,” he told reporters.

That brings us back to the NBA’s Covid rules. ESPN’s Brian Windhorst reports “multiple” Celtics support staff members have tested positive over the last week. That means Horford might’ve been listed as a close contact.

Horford’s timeline for returning to the court will tell us whether he tested positive for Covid or was being held back for precautionary reasons. The NBA allows players to leave Covid isolation five days after testing positive, which would make Horford unavailable for Game 2 Thursday. (Players are still held back for five days even if they're asymptomatic.)

ESPN’s Adrian Wojnarowski reports the Celtics are prepared for the “likely scenario” of Horford staying sidelined through Game 2.

If Horford tested positive Tuesday, he also wouldn’t be able to play Game 3 on Saturday night.

A couple of high-profile NBA players and coaches have tested positive for Covid this postseason. Steve Kerr missed the Warriors’ last three games in the quarterfinals and Paul George missed the Clippers’ play-in game.

Udoka missed his press conference Wednesday due to a non-Covid illness, further adding to the mystery.

Though playing without Horford isn't ideal, it would be potentially catastrophic if other key players missed time. One can assume others players been tested this week, considering the status of the support staff, but who knows?

The Celtics aren’t talking, so it’s up to everyone else to guess.