The 24-year-old was one of several big-money acquisitions made by Everton this past summer.
And the former Manchester United centre-back has looked a very decent addition to an Everton side who clearly have aspirations to qualify for the Champions League come May.
Keane has started all three of the Toffees' Premier League game so far, and fellow centre-back Jagielka believes the young man will be a superb acquisition.
He told Everton's website: "Michael is a great signing. It is great we can go out there and spend that much money on a defender and strengthen after we had a pretty decent defensive record last year – and we will be looking to improve on it this season.
“I already knew Michael, he does not live too far away from me and I have seen him on the golf course a couple of times! He has played with a couple of the lads for England, myself included, and the transition from Burnley to here was quite easy for him.
“It was pretty easy helping him settle in as well. He is a great lad and is going to be a fantastic signing for us.”
Ronald Koeman's side have won one, drawn one and lost one in their first three games so far, but Saturday throws up another big test.
Everton host Tottenham Hotspur at Goodison Park and although Spurs aren't in great form so far, you get the feeling that Mauricio Pochettino's troops would prefer an away game over another one at Wembley at the moment.
The Lilywhites lost against Chelsea and drew against Burnley at home in recent weeks, and an away day might be just what the doctor ordered.