David Maddock of the Daily Mirror made the claim on his personal Twitter page on Friday night.
He will be announced as a Besiktas player at the end of the weekend, after they accidentally announced his capture prematurely.
The deal is said to be a two-year loan deal with an obligation to buy at £9.5m.
Loris Karius will begin medical with Besiktas tomorrow, after arriving in Istanbul, and if no hitches, will be unveiled by end of weekend, on a two year loan deal with contracted obligation to buy for £9.5m #LFC
— David Maddock (@MaddockMirror) August 24, 2018
This sets in motion the exit of Loris Karius, who is reportedly on £25k-a-week at Liverpool. Besiktas managed to mess things up spectacularly when they announced his signing prematurely. However, if all goes well with the medical then he should be unveiled as their player by Monday at the latest. With a contractual obligation to buy, this effectively ends Karius’ career at Liverpool and despite his blunders we imagine the majority of fans will wish him all the luck in the world. He hurt after the Champions League final – as did the fans – and he deserves the chance to resurrect his career away from Liverpool. They’ve moved on with Alisson and now Karius will get to do the same. Some Liverpool fans were surprised that he wasn’t staying to be the number two, but we imagine too much water has passed under the bridge. Simon Mignolet looks like he’ll get another reprieve although he’ll only see first-team action in the cups unless Klopp’s number one gets injured.