Doctor Strange: 7 Post-Credits Scenes They Should Have Used
4. A Strange Vision...
Doctor Strange's day job (besides saving lives) is dabbling in the mystical arts - and under that rather vague banner comes his ability to have visions of the future, sense new information, and in the comics, use a crystal ball - the Orb of Agamotto - for the purposes of clairvoyance.
As a result, he'd be more than capable of envisioning the future of the MCU, which could tease Thanos, the Infinity Gauntlet and the Infinity War.
This would have been a relatively straightforward scene - not unlike Tony's vision of his dead team-mates during Avengers: Age Of Ultron - featuring Strange sitting in the Sanctum Sanctorum, mulling over the Orb of Agamotto. He touches it, and bam - we're greeted by a host of fleeting, blink and you'll miss it images; Strange battling Thanos, Thanos wielding a completed Infinity Gauntlet, and the entire Avengers crew uniting on the battlefield.
This would certainly have been a great way of teasing what's to come without revealing too much, and since the last time we saw Thanos was a year and a half ago, it makes sense time-wise.