"This is what you play golf for, to be in contention," Fox said. "It's been a while since I've been in this position. I'll just go out and enjoy it and see if I can keep playing how I'm playing. I know if I do, I've got a good chance."
The 34-year-old Fox understands the calibre of the chase group, in what will probably be the strongest field on the European Tour all year.
"I [can] go out and play well, try to set the target and make them chase me.
"I certainly hope to be there in the top 50 one day. If I can play well this week, then it's a step forward in that direction.
"If not, it's just good experience and a nice finish to my desert swing because I don't really know when I'm going to come back out here again."
Fox, who took time off to return to New Zealand for the birth of his daughter, had been concerned about his layoff and slow start to 2021 but said he's "very happy" with his two rounds at Royal Greens Golf & Country Club.
Johnson, winner of the inaugural Saudi International two years ago, is one of four top-10 players at the tournament, which is the last of three events in the "Gulf Swing" that launches 2021 on the European Tour.
Fox, ranked 208th after his time away late last year, has another goal in mind as he completes his final event for the foreseeable future, with a hasty exit required on Sunday to make it back to New Zealand in time for his stint in quarantine.
"As long as I can make my flight on Sunday - to make sure I get back into New Zealand."
- With AP
