Atletico Madrid coach Diego Simeone says Diego Costa is the player who has surprised him most in his career.
Costa completed his return to Madrid from Chelsea last week.
Simeone told Cadena Ser: "Last year we were close. I spoke a lot with him. If he had not made the effort this summer the transfer would not have been possible."
When then asked whether Costa is the ideal forward for Atletico, Simeone replied: "Of the players of his level he is the one for us. Another one of that level or better and we would not be able to afford.
"Of all the players I have had he is the one that has surprised me the most. He brings together all the qualities of goals, workrate, effort and leadership."