Rory McIlroy issues warning to PGA Tour over future of prestigious tournament

This means Championship players will not compete in Challenger events and vice versa.

The Scottish Open would be listed as a Challenge competition, missing out on several big names playing due to them being ineligible.

Commenting on the matter, McIlroy said: "We've got to be careful with that because then these national opens lose the fabric of what they are.

"You can't call yourself a national open any more if it's a closed-off tournament and there's a certain number of guys.

"These events need to be treated differently than the Travelers Championship or RBC Heritage or whatever else is going to be in the Championship series."

The Scottish Open has been co-sanctioned by the PGA and DP World Tours in the past four years.

This has allowed players of either tour to play if they are ranked high enough.

Scotland's leading professional Bob MacIntyre said there needs to be "exemptions" for his home Open.

World No1 Scottie Scheffler is featuring in the Scottish Open in the build-up to the Open Championship next week.

The American hopes that tournaments can be organised "to work within the new schedule".

He said: "It's an important one that we keep it in the Championship Series just because you get so many guys that come over here and play the week before [The Open]."

Scheffler explained that it will be "hard to tell" whether the field should include DP World Tour players with the new set-up.

The American continued: "Golf is so difficult to rank players when they are not playing together all the time.

"Having similar guys playing against each other on great golf courses week in and week out is the best way to set up our schedule.

"To have this tournament fit into that mould would be really nice."

McIlroy teed off with MacIntyre for their first rounds, both recording impressive scores, with the Northern Irishman shooting five-under-par and the Scotsman three-under-par.