In a UEFA Cup match against Newcastle United on 8 March 2007, Grétar scored in a 4–2 loss. After the match, Grétar said that AZ would score two goals in the next leg, a prediction that he made turned out to be correct, as AZ went on to win 2–0 and subsequently saw the club go through to the next round. After being out of the first team over suspension, Grétar was featured in the KNVB Cup Final against Ajax, playing 120 minutes and scored in the penalty–shootout, as AZ went on to lose 8–7 as a result.
In a UEFA Cup match against Newcastle United on 8 March 2007, Grétar scored in a 4–2 loss. After the match, Grétar said that AZ would score two goals in the next leg, a prediction that he made turned out to be correct, as AZ went on to win 2–0 and subsequently saw the club go through to the next round. After being out of the first team over suspension, Grétar was featured in the KNVB Cup Final against Ajax, playing 120 minutes and scored in the penalty–shootout, as AZ went on to lose 8–7 as a result.