Rory McIlroy is third in the FedExCup standings-10 C Morikawa (USA), K Bradley (USA), V Hovland (Nor); -9 S Scheffler (USA); -8 A Schenk (USA), R Henley (USA); -7 M Fitzpatrick (Eng), R McIlroy (NI), J Rahm (Spa)Selected others: -6 T Hatton (Eng); -2 T Fleetwood (Eng); Full leaderboardRory McIlroy overcame back issues to fire an even-par 70 and put himself in contention after the first round of the Tour Championship in Atlanta.The Northern Irishman failed to hit a birdie on the outward nine while dropping two shots.But four birdies and two bogeys on the back nine put him within three shots of the lead on seven under overall.Collin Morikawa, Keegan Bradley and Viktor Hovland (-10) are in a three-way tie at the top of the leaderboard.McIlroy suffered the injury while exercising at home on Tuesday and had not practised this week.”My whole lower back spasmed, seized up. I couldn’t move,” McIlroy said. “I honestly couldn’t address the ball this time yesterday. So to get to where I am today is good.”The season-ending tournament uses a stroke-based bonus system, which gives golfers different scores to start their opening round.The starting strokes range from 10-under – given to the FedExCup points leader – to even, given to the last five golfers to qualify for the event. World number one Scottie Scheffler is top of the FedExCup standings with Hovland second and McIlroy third.Scheffler is one shot off the lead at the Tour Championship after carding a one-over 71 at East Lake Golf Club.England’s Matt Fitzpatrick is also in contention after an eagle on the 18th ensured he signed for a three under 67 and is seven under overall.