Is it possible to executing object serialization into JSON asynchronously?

Hello, in the game my team currently developing, we need to serialize an user data object in C# into JSON format. We’re currently using JSON.NET for the serialization process.

We’ve got it working, but the serialization process, this line

string serialized = JsonConvert.SerializeObject(playerData, Formatting.None); 

can take about 300ms, which is visible as a stutter from the player perspective. Is there anyway to make the process ran asynchronously and notify when it’s finished so it does not causing frame spikes?

Thank you and have a good day.

Oh right! I just forgot to call the Async Operation.

private string serialized;

private IEnumerator SerializeJSONStart(){
    AsyncOperation async = SerializeJSON();
        yield return null;

private void SerializeJOSN(){
    serialized = JsonConvert.SerializeObject(playerData, Formatting.None);