Rory McIlroy has work to do if he is to add a fourth title to his collection as he sits way back in tied-23rd after the opening two rounds of the Tour Championship in Atlanta.The Masters champion on three-under par is seven shots off joint-leaders Ryan Gerard and Viktor Hovland after an up-and-down 69 on Friday.A birdie on the first gave promise of launching an attack at the top of the leader board, but it quickly dissipated as he struck a double bogey on the third and then followed it up with another bogey at the fourth.A birdie at the sixth did some repair work as he made the turn at one over and a three at the par-four 12th brought him level for the round.But he bogeyed the next before rescuing his round with birdies at the 16th and 18th to card a one-under 69.Meanwhile, his Ryder Cup team-mate Justin Rose put himself in contention after a scintillating second-round 65.The Englishman fired five birdies in a blemish-free round to move to seven-under, giving himself a chance at winning the $10-million FedExCup playoff series finale at the halfway point.He is three shots off the lead and one clear of Collin Morikawa and Chris Gotterup on nine-under.Rose hit birdies at the sixth, eighth and 11th hole to make his move up the leader board and then added more at the 15th and 18th to card a five-under-par 65.Scottie Scheffler sits on a healthy eight-under after a round of 67 which contained six birdies and three bogeys.Cameron Young is also on eight under after firing the round of the day – a sublime 62.Young peppered his scorecard with six birdies in seven holes and finished with an eagle three on the par-five 18th to put himself in the mix.