NEW YORK -- The Mets' recent flurry of 40-man roster moves was more than procedural. Friday is the deadline for teams to add certain prospects to their 40-man rosters or risk losing them in next month's Rule 5 Draft, and the Mets have several such players -- including top-ranked prospect Amed Rosario -- in line to make the cut.
MLB requires teams to add players who signed at age 18 or younger to 40-man rosters within five professional seasons, or those who signed at 19 or older within four seasons, or they will become eligible for other organizations to select in the Rule 5 Draft. Clubs pay $50,000 to select a player in the Major League phase of the Rule 5 Draft, which is slated for Dec. 10. If that player doesn't stay on the drafting team's 25-man roster for the full season, he must be offered back to his former organization for $25,000.
• Mayo: Top prospects who face 40-man/Rule 5 decision
Though the Mets currently have six open 40-man spots, they'll eventually need to use several of them on incoming free agents -- meaning they cannot protect all of the players below. With that in mind, here's a look at who deadline day might affect:
Amed Rosario, SS
The Mets' top overall prospect, Rosario is the only one on this list assured of a roster spot. He hit .324 over two levels this past season, reached Double-A Binghamton, appeared in the Futures Game and spent most of the summer looking exactly like the Mets' shortstop of the future. There's not much to discuss here. When the dust settles Friday, Rosario will be on the 40-man roster.
Wuilmer Becerra, OF
Many considered it a risk when the Mets left Becerra unprotected a year ago, considering the organization's current No. 7 prospect's strong 2015 season. But 21-year-old position players not named Bryce Harper tend to fare poorly in the big leagues, which is why Becerra ultimately wasn't seclected in the Rule 5 Draft. A year later, the situation remains complicated with Becerra, who hit .312 at Class A Advanced St. Lucie last season but also demonstrated little power before suffering a season-ending shoulder injury. The Mets got away with leaving Becerra unprotected once. They may not be so lucky twice.
Marcos Molina, RHP
Another interesting decision revolves around the Mets' No. 11 prospect Molina, who was well on his way to becoming a blue-chip starting-pitching prospect before Tommy John surgery interfered in 2015. Though Molina has yet to return to competitive action, he is scheduled to do so this summer. A rebuilding club might take a chance on the 21-year-old Molina, whose fastball reached the mid-90s before surgery.

Tomas Nido, C
The Mets' 19th-ranked prospect, Nido took significant strides forward this year as a 22-year-old at St. Lucie, batting .320 with seven home runs in 90 games. It would be a risk for a rival club to carry Nido, raw as he is, on its big league bench all season. But it would also be a risk for the Mets, who are searching for answers at the catching position, to leave Nido exposed.
Chris Flexen, RHP
Another former Tommy John patient, Flexen broke out with a 3.56 ERA over 25 starts at St. Lucie. Though Flexen does not miss many bats, he's a strike-thrower who could one day fill into the back of a rotation. He clocks in as the Mets' 29th-ranked prospect.
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Paul Sewald, RHP
No one on this list is more big league ready than Sewald, who posted a 3.29 ERA over 56 relief appearances at Triple-A Las Vegas, striking out 11 batters per nine innings. Though Sewald doesn't boast the future potential of a starting pitcher like Molina, he's a strong bet to get snapped up if the Mets leave him unprotected.
Champ Stuart, OF
An elite defender and baserunner, Stuart stole 40 bases in 114 games between two levels this past season. But his bat will likely discourage teams from selecting him; Stuart hit just .240 with a .663 OPS, making him a tough sell on a big league roster.
Phillip Evans, IF
Evans wasn't much of a consideration for protection a year ago. But he broke out in 2016 with a .335 batting average and eight home runs at Binghamton, putting him in line to reach Las Vegas at age 24. That may not entice a team to Draft him, but it should at least be enough to give the Mets pause.