Craig Gilroy backs Paddy Jackson to fill Johnny Sexton's boots in South Africa

Ireland wing Craig Gilroy is backing his Ulster team-mate Paddy Jackson to deliver when they take on South Africa in a three-Test series which begins in Cape Town on Saturday.

The 24-year-old fly-half is set to feature in the first Test against South Africa ahead of Ian Madigan after Johnny Sexton was ruled out of the tour with a shoulder injury.

This will also be the first time Jackson will begin at number 10 since the World Cup warm-up game against Wales in August.

After making his Ireland debut in 2013, Jackson has 13 caps to his name and has scored 66 points in it. However, he had a productive 2015-16 season with Ulster in Pro12 and is fourth in the list of leading point scorers.

On the other hand, Madigan, who was added to the Ireland squad as a replacement has been on the sidelines for the most part of the previous season for Leinster ever since the return of Sexton and has made a switch to Bordeaux Bègles for the upcoming season.

"He's been fantastic. He's been a joy to play with," he said.

"It's not just off the back of this season that I say this, I played with Jacko at school, underage level, under-19s, under-20s, provincially and internationally.

"He's a joy to play with, I've always rated him so highly. I always enjoy playing with him and no doubt if he gets an opportunity I think he'll take it.

"I think this has probably been his best season on a personal level.

"Not only was he able to deliver on the pitch physically, but he stepped up as a leader. He spoke well to us guys post-game, at half-time and he talks well on the pitch and commands the plays that he wants.

"He delivers with ball-in-hand, his kicking game has been fantastic as well.

"Les knows Jack is more than capable.

"He has that smart rugby brain to make the decisions to take the ball to the line or if he decides to go himself, do you know what he's a tight wee man and he's a lot quicker than he looks.

"He's hard, Jacko. Sometimes he has a laugh at himself, but he'll get down to the nitty-gritty stuff and put his body on the line."

Ireland assistant coach Simon Easterby, who has seen Jackson in close quarters last year, believes the fly-half will be up for the challenge against the Springboks.

"Spending time with Paddy, (I've noticed) his game is growing and that leadership is improving," he said.

"I was up at the Toulouse game during the European Cup. He carried flat to the line, his distribution was excellent, his kicking skills were good.

"He's getting a real good balance to his game and I think he's had time in the squad to look at what Johnny does and how he approaches it, but he's got to be himself and he's got to put his own stamp on it.

"Like Mads, they both have the ability to play really flat and challenge the defence but they also have the ability to play the percentage game."

Easterby also admitted that losing a player of Sexton’s calibre will be a big blow for Ireland but at the same time hopes the replacement player grabs the opportunity given to him as they look to build the team for the future.

"It allows us to see something else outside of what we know Johnny can give us," he said.

"That ability for those guys to step up will go a long way in the next couple of years for their continued involvement and development in the squad and that's only a good thing.

"It's a real positive that we can take out of the next few weeks."