Sunderland are now strong contenders to sign an ‘excellent’ free agent who has been playing under Dick Advocaat. Sunderland will be hoping to have some cash to spend this summer, with Jack Clarke likely to be on his way out. The Black Cats could make eight figures from his exit, while Jobe Bellingham has also been linked with a £20 million plus move away from the club. Kryil Louis-Dreyfus will definitely need an influx of cash to drastically improve the squad before next season, having endured their most difficult campaign since his arrival. However, that doesn’t prevent Sunderland from dippin…