JAMES TAVERNIER insists Rangers must raise their levels once again after another below par performance in their win over Partick Thistle.

Michael Beale’s side secured a 3-2 victory at Ibrox to book their place in the draw for the last eight of the Scottish Cup on Monday evening.

Antonio Colak, Malik Tillman and James Sands were on target on a headline-grabbing afternoon as Rangers toiled for long periods against their Championship visitors.

Beale expressed his frustration with the showing once again and captain Tavernier, who missed a second half penalty, knows Rangers must move through the gears quickly this term.

Tavernier said: “It’s probably more disappointment. We’re through to the next round but it’s the level of performance that’s really disappointing. We made it really hard for ourselves today which we didn’t need to.

“Obviously we’re through to the next round which is the main thing. But there’s a lot more improvement that we can do. We’ll keep working hard to do that.

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“It’s disappointing because we’ve shown consistency in terms of results. We have spells of really good play but we almost take our foot off the gas and make it harder for ourselves.

“We showed a really good level of performance against Hearts and we need to continue working to display that through the 90 minutes.

“We know there’s work to be done and we’re improving all the time but it’s those small margins when we need to keep that constancy of performance up.”

The performance of midfielder Nicolas Raskin was one of the main positives for Beale to take as the Belgian made his first start following his move from Standard Liege.

Raskin built on a solid opening 45 minutes with an impressive showing after the break and Tavernier has been encouraged by the way he has adapted to life at Ibrox.

He said: “He’s another great lad who has settled in well.

“He got an assist for Tony’s goal but it probably wasn’t the afternoon I wanted to give him with the way we all played.

“But credit to him he had a good game and hopefully he can build on that.”