Off contract from Manchester United, Lindelof signed for Villa after recommendation from his former Old Trafford teammate Mata.
Emery said: "I called Juan Mata, his team-mate at Manchester United three or four years ago, and I coached Mata in Spain. He is a fantastic guy, an intelligent guy. I called him speaking around the possibility to sign Lindelof, as a person, as a player, the commitment.
"Everything he told me, now we are watching it. Fantastic guy, very professional, respectful. He was being passion and adapting to play in the right side, and when we needed him because we had those two injuries to Tyrone Mings and Pau (Torres), he played in the level we expected.
"And of course, I am so happy how he's helping us and I told him, 'you set the level here, now you can't get under this level'."