Law, a Manchester United supporter, says the Gers' biggest problem right now is their 'huge' lack of confidence.
Rangers sit third in the Scottish Championship, some 24 points off league-leaders Hearts. They are also four points behind second-placed Hibernian, although they have three games in hand over Hibs.
And Law feels Kenny McDowall's side have been suffering from a loss of confidence over the past couple of months, citing Di Maria as a similar example south of the border at Old Trafford.
"Confidence is a huge thing and it's undoubtedly been down in the past couple of months. You can see that elsewhere in football too. I'm a Manchester United fan and you look at them and see the stick that Angel Di Maria is getting and that's on another level," he said.
"When you lose your confidence in football it's a hard thing to get it back as you can't just switch it on and off. Unfortunately it's been down recently and we've began to rebuild that."
Di Maria has struggled of late in a Manchester United shirt, with many at a loss at to why the summer signing from Real Madrid isn't tearing up the Premier League as the majority of onlookers predicted he would.
The Argentine's struggles have been accentuated due to his heavy price-tag. He certainly doesn't look like the player that proved so vital during last season's Champions League final.
As for Rangers, they'll need to address their confidence issues sooner rather than later as the business end of the campaign approaches.