Web API 2 POST request simulation in POSTMAN Rest Client

Well, make sure that you specify raw and set the Content-Type request header to application/json. And then go ahead and specify the body of the POST request that will match your view model structure:

{
    "id": 1,
    "key": "some key",
    "name": "some name of course",
    "password": "the hyper secret",
    "teamId": 256,
    "stat": {
        "playerId": 115,
        "firstName": "John",
        "lastName": "Smith",
        "title": "His Royal Majesty",
        "emailAddress": "john.smith@buckingampalace.com",
        "phoneNumbers": [
            { "value": "123", "extension": "05" },
            { "value": "456", "extension": "45" }
        ],
        "teamId": 678
    }
}

So your actual payload’s gonna look like that at protocol level:

POST /NFL/Players HTTP/1.1
Host: localhost:9888
Content-Type: application/json
Content-Length: 582

{
    "id": 1,
    "key": "some key",
    "name": "some name of course",
    "password": "the hyper secret",
    "teamId": 256,
    "stat": {
        "playerId": 115,
        "firstName": "John",
        "lastName": "Smith",
        "title": "His Royal Majesty",
        "emailAddress": "john.smith@buckingampalace.com",
        "phoneNumbers": [
            { "value": "123", "extension": "05" },
            { "value": "456", "extension": "45" }
        ],
        "teamId": 678
    }
}