The country singer has announced he will play Monday 28 July in addition to his gigs on the 25th, 26th and 27th, which sold out 90 minutes after going on sale last week.Tickets for the extra date are to be made available at 9am this Thursday.Promoter Peter Aiken said: "It is hard to believe that an artist could play four nights in a row at Croke Park, but thanks to the co operation of Croke Park and the huge support of the fans we are delighted to be announcing this fourth date for The Garth Brooks Comeback Special Event."Speaking to Frank Mitchell on U105 following the announcement, Garth said he felt very "fortunate" to be allowed to perform another night at Croke Park."If you look up at cloud nine, that's where I'm at," he said."A week or so ago I woke up to the news that we were going to play three nights in Ireland and I couldn't believe and then we got a phone call saying there was a lot of people looking for tickets."We are very excited, we're humbled, we feel blessed and, most of all, we are just as happy has can be."I think everyone (in Ireland) is crazy to tell you the truth. I would have never guessed I would sell out three nights, so the fact that they are asking for four - you got to be crazy!"