How can I mock webClient in my unit test for the class below

@Service
public class Service {
  private final WebClient webClient;
  public Service(String baseUrl) {
    this.webClient = WebClient.builder().baseUrl(baseUrl).build();
  }
  public User getUser() { webClient.get().bodyToMono(User.class).block(); }
}

1. ReflectionTestUtils works, is there a better way?
2. No constructor injection of WebClient Service(WebClient webClient)

Any solutions?