FOXBORO � The story surrounding Armond Armstead has started to read like a chapter out of a mystery novel. There have been twists, turns and multiple theories, but few answers.The defensive tackle has...

FOXBORO � The story surrounding Armond Armstead has started to read like a chapter out of a mystery novel. There have been twists, turns and multiple theories, but few answers.

The defensive tackle has turned into the biggest enigma on the Patriots over the last year and fans on Twitter only add to the speculation.

�Bigfoot is easier to find than Armond Armstead,� one person wrote. Another Tweets, �Does Armond Armstead exist?�

The questions, though arbitrary, are in a sense valid. For a man who stands 6-foot-6 and weighs 305 pounds, this 23-year-old has been hard to find.

After signing with the Patriots last season, following a stint in the Canadian Football League, Armstead spent the season on the nonfootball illness reserve list with an unknown infection and was never seen in the locker room. It was reported that Armstead was �on track� to join the Patriots for their offseason workouts this spring and by all accounts � at one point � he was present at Gillette Stadium.

He was seen on May 30, the media�s first access to the Pats organized team activities. Wearing No. 97, Armstead was visible with the other rehabbing players who soon vanished into the Dana Farber Field House.

But Armstead hasn�t been seen since, which begs the question � what is going on with Armond Armstead?

A call to his father, Guss Armstead, in California provided few answers. When asked where his son was and how he was doing, he replied, �We�re not talking to anybody about that. We�re just not talking. You�ve got to talk to the Patriots.�

In training camp last year, the Patriots made one statement on Armstead when he was placed on the nonfootball illness list: �Armond Armstead had surgery to treat an infection. Armond is in good condition and is expected to make a full recovery. A timetable has not been set for his return.�

We heard little about the California native since. On Tuesday, prior to the team�s first minicamp practice, Bill Belichick was asked about the lineman.

�Armond�s really worked hard. He�s had a lot of adversity personally that he�s had to deal with. Unusual compared to most other players,� Belichick said. �He�s had a great attitude, worked hard. He�s really done everything we�ve asked him to do.�

But when the Patriots took the field, Armstead was nowhere to be found.

There were multiple rumors surrounding the disappearance of Armstead last season. Did he catch MRSA, a potentially deadly staph infection that is resistant to antibiotics? The Tampa Bay Buccaneers, who had a joint training-camp practice with the Patriots, had an outbreak of it.

His absence, however, is likely connected to a previous heart condition.

Armstead suffered a heart attack in 2011 and missed his senior season at USC. The defensive tackle is currently suing the school, alleging that team doctors treated him with Toradol and the drug led to his heart attack. His heart was the reason he went undrafted, causing him to sign and play in the CFL with the Toronto Argonauts for a season.

In the lawsuit, titled, �Armstead v. University of Southern California,� Armstead is represented by Roger Dreyer and Robert Bale of Dreyer Babich Buccola Wood Campora LLP. According to the Los Angeles Daily News, Bale told Los Angeles Superior Court Judge Yvette Palazuelos that his client was still waiting to be cleared by doctors to play. That was in April.

Bale also noted that Armstead was having clotting and other medical issues, which they�re alleging is related to the Toradol use. That trial date was reset from June 23 to March 23, 2015.

Calls to Armstead�s lawyer were not returned.

All jokes on Twitter aside, it seems like this player might be dealing with serious medical issues. During the week Armstead wasn�t seen at OTAs, his father Tweeted that he was in Boston, and then three days later, on July 9, wrote the following:

�Rough week for our family, God spoke to me and said continue to live out your faith. So as for me and the Armstead house we will [praise the Lord].�

Belichick told reporters last year that Armstead would have been next on the Patriots� depth chart behind Vince Wilfork and Tommy Kelly. That only added to his allure.

Much like Jeff Demps, the track and field athlete signed and then traded to Tampa Bay in the LeGarrette Blount deal, there�s a certain appeal to this undrafted free agent. But unlike Demps, who was seen in the Pats locker room while on the injured reserve, Armstead has � for the most part � been missing.

By all accounts, Armstead was present in Foxboro for the team�s offseason workouts, like he was last year. Though he�s never so much as appeared in a preseason game, he�s made an impression on his teammates.

�I think that he�s a young kid who has done a great job of trying to come into the Patriots and work hard,� Rob Ninkovich said. �Obviously there have been issues that are out of his control. I don�t want to speak on his behalf of anything that�s ever happened to him, but as far as his personality goes, he�s a teammate that you want to have around. He�s working hard and trying to get better. You really can�t ask for anything more.�

Belichick wasn�t revealing if Armstead could be expected to practice this week. The coach simply responded, �We�ll see how it goes.�

And so the mystery continues.