Sanchez wrote in the Daily Star Sunday: "Alex is a wily old fox. I found that out during my time as Fulham manager.
"Previously I had managed Northern Ireland and handed a then unknown Jonny Evans his debut in a match against Spain, which we won 3-2.
"I was invited into Alex's room after the game for a drink and we got talking about players.
"I asked if Evans was available and said I was willing to pay three to five million pounds.
"Without blinking Alex informed me they had been offered £12m for him.
"He was basically telling me to back off - or deliver. He was testing me. All in a nice way, of course."