Barry Ferguson had to be frank when describing Rangers' display against Heart of Midlothian - simply stating "it was really worrying".

The Light Blues got the narrow win at Ibrox, thanks to Cyriel Dessers' goal on six minutes. It was the perfect start for Rangers - who are nine points behind Scottish Premiership leaders Celtic and Aberdeen. 

But they failed to build on their early momentum, creating a nervous and anxious feel among players and supporters throughout the second half before eventually managing to get over the line.

"That second half performance was really worrying," the former Rangers captain told the Go Radio Football Show. "I'm not going to sit here and kid anybody on, it was.

"I thought the first half was OK. You get off to a great start and you want to see them kick on and get the second and third goal, and then put Hearts to bed. But it just kind of falls away in the second half.

"Rangers became really wasteful and sloppy. They looked a bit nervy at times and obviously the fans were getting a bit twitchy in the stands. So, it has to be better.

(Image: PA)

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"Going forward, the problem that they've got is, looking at the game on Thursday night, I thought Rangers were really good on Thursday night against a good Olympiacos team.

"I know it's only three days later, but you need to have at least a level of consistency and that's been Rangers problem. 

"I think they play better in Europe. If you look at the European games, certainly going by Thursday night, Olympiacos were wide open and Rangers are OK with that. 

"If teams come and sit behind and be really solid and compact, Rangers do struggle at times. So they need to find a solution because the vast majority of teams that come to Ibrox are going to play like that."