AudioCache

import 'package:flutter/material.dart';
import 'package:audioplayers/audio_cache.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  static AudioCache _audioCache = new AudioCache();

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _audioCache.play('assets/jogando.mp3');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text("player")
      ),
    );
  }
}