Former Rangers striker Kris Boyd says the Ibrox side need to produce 90-minute performances to end their inconsistency.
Pedro Caixinha's team have not won three successive games since he took charge in March.
Rangers visit Partick Thistle in the League Cup on Tuesday and then host Celtic in the Premiership on Saturday.
"There's a common theme that they start well but they aren't finishing well," said Boyd, scorer of 138 Rangers goals.
"Why are they not seeing games through?
"There's been large periods of games where Rangers have dominated and done well but they've not taken control of them."
After an early Europa League exit with an aggregate defeat by first qualifying round opponents Progres Niederkorn, Rangers opened their Scottish Premiership campaign with a 2-1 win at Motherwell and followed that with a 6-0 victory over Dunfermline Athletic in the League Cup.
Defeat by Hibernian and a draw with Hearts followed before wins against Ross County and Dundee.
But Partick Thistle held Rangers to a 2-2 league draw on Friday.
"At Motherwell, they dominated the first half, could've been out of sight and then lucky to hang on," Kilmarnock striker Boyd said on BBC Radio Scotland's Sportsound.
"Hibs, started really, really well - lost that game. Hearts, it was 0-0 but by all accounts started that game reasonably well. The 45 minutes at Dingwall [against Ross County], could've easily been out of sight.
"This is a big week. You look at Rangers' next fixtures after that. They've got a tricky game at Hamilton, then they go to St Johnstone, then Aberdeen before finishing the first set of fixtures at home to ourselves.
"There's not any easy games in there either, especially the next few."
Former Hearts and Hibernian midfielder Michael Stewart says the next two games could be "defining" for Portuguese Caixinha.
"It's a huge week, it could be a defining week for Pedro Caixinha," he said on Sportsound. "Massive couple of games coming up.
"All season long, since the start of the league campaign, Pedro Caixinha has really needed to try and build up a head of steam and get some consistency in results and he hasn't been able to do it.
"In the next week he has two huge games that if he's able to win both of them, then all the doubts get parked to one side and people really start to believe that he has got longevity in the job.
"If he's to lose both of them, then it could be terminal. I don't think he would be sacked within days or a week or whatever but it would be a case of when rather than if he was to go.
"If, as I probably expect would happen, that he sees the team through to the League Cup semi-final on a narrow victory at Firhill and then is beaten by Celtic, we end up in a position where it's a bit of a state of flux.
"What is it that's happening at Rangers? Where's the direction? There's been moments of good play in Rangers this season in the games in the league but they still look very fragile and vulnerable.
"There's been some good signings, no doubt about that. I think [Alfredo] Morelos has shown himself to be an astute piece of business. You look at [Graham] Dorrans and [Ryan] Jack - clever signings.
"For every one of them, there's ones that you would think the Rangers support are asking questions about as well. There's a real mixed bag and the next week perhaps might start to bring a bit of clarity to where they're going."