AUGUSTA, Ga. — The door was open all day for Scottie Scheffler at Augusta National Golf Club.

The reigning Masters champion failed to take advantage time and time again, leaving him seven shots behind leader Rory McIlroy with a round left in his bid to join Jack Nicklaus as the only players to win the green jacket three times in a four-year span.

Scheffler wasn’t particularly sharp Saturday and failed to give himself many birdie opportunities. In fact, he spent the vast majority of the day scrambling to save par, and the reality is his par round of 72 could have been much worse.

He was at 5-under 211 for the tournament with 18 holes to go.

“At times I felt good, at times I felt bad,” said Scheffler, whose birdie on No. 2 suggested the start of a potential charge that never happened. “I just couldn’t really get anything going. I had to scramble a lot today, actually. I got off to a good start, but after that I didn’t really feel like I gave myself enough opportunities, and the opportunities that I did have, I didn’t really quite take advantage of.”

A comeback isn’t impossible for Scheffler, who has been No. 1 in the Official World Golf Ranking for two years.

History shows anything can happen on a Sunday at the Masters.

In 1956, Jack Burke Jr., a 33-year-old pro who hadn’t won a tournament since 1953, trailed leader Ken Venturi by eight strokes entering the final round and rallied to win after shooting a 71. Venturi, then a rookie, collapsed with an 80.

Scheffler, who is tied for seventh, would need a huge day for himself — probably even better than a 66, his personal best for a round at Augusta — and for several others to collapse, including McIlroy, who seems intently focused on snapping his decade-plus drought without a major championship and joining an elite group of golfers who have won the career Grand Slam.

McIlroy, a four-time major winner, started the day with six straight 3s and surged to the lead while shooting a 66. He had a two-stroke lead over Bryson DeChambeau. Corey Conners was another two shots back, with Ludvig Aberg and Patrick Reed six behind McIlroy.

Scheffler was one of four players tied for sixth.

While he knows a comeback is a long shot, Scheffler insisted that won’t change his game plan entering the final 18 holes.

“There is a school of thought when it comes to that, but when I think about last year, I had two big comebacks — one at The Players Championship and one at the Olympics,” he said. “Did I press or force things? Did I play more aggressive? Not really. I just gave myself the most amount of opportunities, and I hit a lot of good shots and was able to hole some putts.”

And with that, the 28-year-old Texan was heading to the practice range.

“I’m going to go hit a few balls tonight, see if I can get a good feel going into tomorrow,” Scheffler said, “and then you never know.”