There's plenty of decent interims around if our primary target isn't immediately available 'till the summer.
Look at it from a career planning perspective. He's on his way to win another double and make a good CL run. It's a risk for him and his reputation to hop on board now.
He's never managed in England or the PL or come in mid season in a high pressure job. Why would he not take the trophies and the plaudits for a good showing in the CL, so he can weigh his options in the summer when he has a full pre season and a summer transfer window at a variety of clubs?
There's no confirmation that he isn't available. Our board just hasn't shown any interest and it's rumoured it's because of his lack of PL experience.