It was McIlroy's first tournament since his final-day disappointment at last month's Open Championship.

JJ Spaun carded a 67 to lead on 11 under, with fellow American Troy Merritt and Austrian Sepp Straka one shot back.

World number one Scottish Scheffler also missed the cut on one under, as did Scotland's Russell Knox on level par and Justin Rose, who went round in 75 to slip to six over.

The St Jude Championship at TPC Southwind is the first of three tournaments to decide the Tour champion, with the winner picking up $18m (£14.8m).

McIlroy, who last missed the cut at the Valero Texas Open in March, shot four birdies - including two in the first two holes - but bogeys on the sixth, ninth and 18th cost him.

Although Spaun bogeyed the seventh and 12th, five birdies took him clear of the field as overnight leader Kim Si-woo from South Korea faded to five under courtesy of a 73.

Merritt mixed six birdies and an eagle with three bogeys in his 65, while three birdies and an eagle in the first six holes set American Denny McCarthy on the way to a fine 65 and nine under overall, two shots behind Spaun.

Australian Cameron Smith, the Open champion and world number two, also went round in 65 to move to within three shots of the lead.

Tyler Duncan's flawless seven-under 63 took him from 68th overnight to a share of ninth on seven under.

Matt Fitzpatrick moved to six under, with fellow Englishman Tyrrell Hatton on five under and Ireland's Shane Lowry a further one stroke back.