NEW YORK -- After 17 months, the Mets finally have a concrete diagnosis of what's been ailing infielder Jed Lowrie. A doctor unaffiliated with the Mets confirmed that Lowrie is suffering from "PCL laxity" in his left knee, which general manager Brodie Van Wagenen defined as "looseness" in the posterior cruciate ligament.

When Lowrie wears a bulky rehab brace, he is able to mitigate the pain. When he replaces it with a smaller brace that is functional enough for game play, his pain increases.

"The challenge will be can we get him to a point where he can run the bases and play defense at the speed and at the efficiency level that needs to happen to be a Major League level," Van Wagenen said. "If we can get to that point, I don't think it will take long for him to get ready because of the offensive capability."

Lowrie, who opened the season on the 10-day injured list, plans to talk in the coming days with both Mets team physician Dr. David Altchek and the doctor who provided his second opinion, with the goal of determining his next steps. Van Wagenen did not dismiss the possibility that surgery could be an option, but the GM also offered optimism that Lowrie can contribute to the Mets this year.

So far, the Mets have resisted shifting Lowrie to the 45-day IL despite their need for roster flexibility.

"We think the player can help us," Van Wagenen said. "We saw it in Summer Camp that, offensively, he can be a value add to the team. So the goal would be to get him back to contribute, but the conversations that come from the doctors here over the course of the next couple of days will determine what the timeline is based on the course of action."

A career .261 hitter over 12 big league seasons, Lowrie has taken a total of eight plate appearances -- all last September -- since signing a two-year, $20 million contract to shore up the Mets' infield in January 2019. His knee issues initially surfaced weeks after his signing, when Lowrie reported to his first Mets Spring Training. However, Van Wagenen has insisted that the Mets performed a thorough examination of Lowrie at the time.

Van Wagenen said he does not second-guess the signing.

"We're seeing now, and we saw it last year as well, is the importance of versatility," the GM said. "Jed being a switch-hitter that can play all three infield positions was a strategic move to give us depth and versatility in the infield. It was important then. It's important now. And it's been disappointing to him, and obviously disappointing and frustrating to everyone involved that we haven't been able to see him perform in that role."

Roster moves aplenty
The Mets made four 30-man roster moves before Thursday's game, swapping out a chunk of their active roster.

Rather than continue to progress day-by-day with infielder Eduardo Núñez, who injured his left knee last Sunday against the Braves, the Mets placed Núñez on the IL with a contusion. To replace him, they called up veteran Brian Dozier, a Minor League signing in the final days of Summer Camp.

Manager Luis Rojas immediately placed Dozier, a career .270/.354/.500 hitter against left-handed pitching, in the starting lineup against Red Sox lefty Martín Pérez.

"Obviously, he's got pedigree," Van Wagenen said. "This guy's always been able to hit, particularly against left-handed pitching. So when we looked at the balance of our infielders with a lot of left-handed hitters, we felt like Brian gave us a real threat from the right side of the plate."

After requesting his release from the Padres earlier this month in what he called a "debacle," Dozier debated sitting the season out due to concerns about his pregnant wife. But after many conversations, Dozier decided to return, choosing the Mets in part based on the strictness of their COVID-19 protocols.

A former All-Star and American League Gold Glove Award winner with the Twins, and a World Series champion coming off the bench last year for the Nationals, Dozier is best known for his power -- an average of 27 homers per season since 2013.

"Whatever the team needs in any kind of situation … whatever the team needs to try to win, I'm here," Dozier said.

In an unrelated move, the Mets recalled left-handed reliever Daniel Zamora to replace righty Hunter Strickland, whom they designated for assignment.

Bigger and safer
During their first road trip of the season, the Mets took a caravan of six buses to Boston, with no more than 10 players or staff members allowed on a bus. Since that arrangement wasn't possible for their second trip to Atlanta, the Mets found a different way to take precautions.

Rather than fly in their usual chartered Boeing 737 plane, the Mets are flying a larger Boeing 757 that they typically only reserve after rosters expand in September.

"The conversation never ends," Van Wagenen said of the Mets' safety protocols. "Reminding and reminders are constant. That goes from my chair to the coaching staff to the performance staff, and even the players to one another. They are mindful of what's going on around them."

Depth add
The Mets on Thursday made their signing of catcher Bruce Maxwell official, inking him to a Minor League deal. Van Wagenen indicated that Maxwell could see time in the big leagues later this season.

"The catching position obviously is a valuable one, and one that when we were looking at the available options out there, Bruce is a guy that we've had interest in and have tracked in the past," the GM said. "We think that from a power standpoint, he provides some good insurance."

A career .240/.314/.347 hitter who has not appeared in the Majors since 2018, Maxwell will need time to ramp up at the Mets' alternate site in Brooklyn. The team could have a need in the coming weeks if a 40-man roster crunch forces them to designate either René Rivera or Tomás Nido for assignment.

From the trainer's room
Marcus Stroman (left calf tear) will throw live batting practice on Friday, facing hitters for the first time since landing on the IL. Stroman has been throwing off a mound with no issues, but he must prove he is able to field his position before the Mets will consider activating him. For now, they have no timeline for his return.

"The only way he knows how to play is full-throttle," Van Wagenen said. "We need to make sure that when he does show that burst, that we're not risking re-injury that would keep him out for a longer period of time. So far, so good."

Less serious is outfielder Jake Marisnick's left hamstring strain, which prevented him from playing at 100 percent over the first week of the season. Van Wagenen indicated that Marisnick should be good to go when eligible to come off the IL on Aug. 8.