PREVIEW: Ireland v Wales
Gatland felt hard done by when he was not kept on as Ireland coach with his Irish assistant Eddie O'Sullivan replacing him in 2001 after three years in the role.
Now the Wales coach has the chance to end Ireland's Grand Slam hopes and inflict the hosts' first Six Nations home defeat since Joe Schmidt took over after the 2013 Six Nations.
Adding extra spice, Horgan told AFP, is that Gatland and Schmidt are two of the men in the running to be next All Blacks coach.
"There is a bit of history (Gatland and Ireland) and if there is a grudge match in the Six Nations then this is it," Horgan told AFP.
"This is definitely the saltiest match of the Six Nations."
Warren Gatland named Dan Biggar at flyhalf after recovering from a spell on the sidelines following a shoulder injury suffered on duty with the Ospreys.
The 28-year-old was hit hard by Fritz Lee of Clermont Auvergne in January and was expected to miss the first three rounds of this year's Championship.
In the end, Biggar sat out only the games with Scotland and England.
Biggar will win his 61st Wales cap in Dublin and will go head-to-head with Ireland's Johnny Sexton, a man he toured New Zealand with as part of last year's British & Irish Lions squad.
"Johnny is an absolutely fantastic player, you can see how important he is for Ireland and Leinster," Biggar said.
"He is a vital cog, along with Conor Murray, so we know we are up against two of the best in the business. And I like Johnny a lot. He has that streak in him where he knows exactly what he wants.
Wales know victory is essential if they are to keep their title hopes alive. To do so would also end Ireland's Grand Slam dream.
"Any Six Nations match is extremely special anyway, but when you play a top team like Ireland away from home, we know it's almost like a cup final for us," Biggar said.
"If you lose it's going to be very difficult to finish on top in the tournament – but if you win, you've got two home games to come against Italy and France and you have set yourself up incredibly well.
"That's the biggest carrot for us. We need to make sure we enjoy the occasion as well. I have been involved in a lot of big games where you go out and you just don't want to make a mistake.
"You're uptight and tense and one of the good things about the group we've got at the minute is we've got a lot of boys in the squad who won't feel like that.
"They'll look at it as just another game and that's how we need to approach it."
Ireland coach Joe Schmidt made five changes to the side that thrashed Italy 56-19 to make it two wins from two.
Andrew Porter will have to fill the sizeable boots of British and Irish Lions star Tadgh Furlong when he makes his first Six Nations start against Wales at Lansdowne Road on Saturday.
The 22-year-old, a relative novice at tighthead prop, impressed against Italy after Furlong had to go off in the fourth minute with a hamstring problem and will be joined by centre Chris Farrell, who comes in for the injured Robbie Henshaw, in making their first Six Nations starts.
Other changes from the starting XV see CJ Stander return at No.8 instead of Jack Conan, James Ryan replace the injured Iain Henderson in the second row, and veteran prop Cian Healy come in for Jack McGrath.
"Tadgh was close but we decided not to risk him and to wait for the Scotland match in a fortnight," said Ireland head coach Joe Schmidt.
"Andrew (Porter) did a sterling job against Italy and acquitted himself really well. This will be a step up but it is a learning process for him and nowhere else better to do so than against a tough team like Wales."
Farrell, who only made his debut against Fiji last November, will form an inexperienced partnership in the centres with Bundee Aki, although the latter sparkled in the Italy match as the New Zealand-born back scored his first try for his adopted country while setting up another.
"Losing three world-class players is tough (Henderson, Henshaw and Furlong) but we are focused on those who are playing," said Schmidt.
"Chris Farrell has been a long-term project. We are short on experience, they are welcoming back three Lions while we are losing three. Not ideal but nowhere better to carry on the learning curve."
Players to watch:
For Ireland: As always the impressive Christiaan Stander will be a huge challenge for Wales. While Christ Potter – whose making his first Six Nations start- will have a lot to prove in the absence of British and Irish Lions start Tadgh Furlong. The hardcore experience of captain Rory Best will be vital to side. Other usual suspects are the likes of halfback pair Johnny Sexton and Conor Murray.
For Wales: The inclusion of experience Dan Biggar at flyhalf indicates the importance of the player in the Welsh set-up. Leigh Halfpenny at fullback will also be a valuable asset for the kicking department. However, the loose trio – Ross Moriarty, Josh Navidi, and Aaron Shingler – will be vital for Wales.
Head to head: As always the biggest battle will be at halfback with Wales' Dan Biggar and Gareth Davies trying to gain the upper hand on Ireland's pair Johnny Sexton and Conor Murray. The battle in the pack – between Andrew Porter, Rory Best and Cian Healy and Wales' Samson Lee, Ken Owens, and Rob Evans – will also be something to look forward too, however, Ireland's pack do have a slight advantage.
Recent results:
2017: Wales won 22-9, Principality Stadium
2016: Draw 16-16, Aviva Stadium
2015: Wales won 16-10, Aviva Stadium
2015: Ireland won 35-21, Principality Stadium
2015: Wales won 23-16, Principality Stadium
2014: Ireland won 26-3, Aviva Stadium
2013: Ireland won 30-22, Millennium Stadium
2012: Wales won 23-21, Aviva Stadium
2011: Wales won 19-13, Millennium Stadium
2011: Wales won 22-10, Westpac Stadium
Prediction: This is one of the toughest match-ups. Ireland have yet to suffer a Six Nations defeat, while Wales will be eager will be more eager to produce a win after their controversial loss to England last week. Added value is this fixture will be Warren Gatland's 100th game in charge and Wales should win by five points or less.
Teams:
Ireland: 15 Rob Kearney, 14 Keith Earls, 13 Chris Farrell, 12 Bundee Aki, 11 Jacob Stockdale, 10 Johnny Sexton, 9 Conor Murray, 8 Christiaan Stander, 7 Dan Leavy, 6 Peter O'Mahony, 5 Devin Toner, 4 James Ryan, 3 Andrew Porter, 2 Rory Best (captain), 1 Cian Healy.
Replacements: 16 Sean Cronin, 17 Jack McGrath, 18 John Ryan, 19 Quinn Roux, 20 Jack Conan, 21 Kieran Marmion, 22 Joey Carbery, 23 Fergus McFadden.
Wales: 15 Leigh Halfpenny, 14 Liam Williams, 13 Scott Williams, 12 Hadleigh Parkes, 11 Steff Evans , 10 Dan Biggar, 9 Gareth Davies, 8 Ross Moriarty, 7 Josh Navidi, 6 Aaron Shingler, 5 Alun Wyn Jones (captain), 4 Cory Hill, 3 Samson Lee, 2 Ken Owens, 1 Rob Evans
Replacements: 16 Elliot Dee, 17 Wyn Jones, 18 Tomas Francis, 19 Bradley Davies, 20 Justin Tipuric, 21 Aled Davies, 22 Gareth Anscombe, 23 George North
Date: Saturday, February 24
Venue: Aviva Stadium, Dublin
Kick-off: 14.15 (14.15 GMT)
Expected weather: Partly cloudy. High of 5°C and low of 1°C
Referee: Glen Jackson (New Zealand)
Assistant referees: Pascal Gaüzère (France), Matthew Carley (England)
TMO: Rowan Kitt (England)
Agence France-Presse & @rugby365com
