ALL the talk has been about dressing room leaks. It was the Rangers’ defensive line that was plugged in Perth, though.

And a much-needed clean sheet proved to be the foundations upon which a crucial win was secured as Pedro Caixinha’s side ran out deserved 3-0 winners over St Johnstone.

The focus hasn’t always been on the football for boss Pedro Caixinha in recent weeks as he has had to address murmurs of discontent in his ranks and revealed he thought he had a mole in the Ibrox camp last term.

For 90 minutes on Friday night, there was only one concern for the Portuguese. It wasn't a perfect performance, but the three points were pleasing.

With his side six adrift of Celtic and Aberdeen before a ball was kicked here, Caixinha would have been well aware that the spotlight was firmly on him and his players.

The recovery from the Old Firm defeat last month was started against Hamilton last time out and it had to be continued here, especially with the Betfred Cup semi-final with Motherwell to come a week on Sunday.

If Rangers are to challenge at the top of the table and finish best of the rest this term, this was the kind of test that they simply have to pass. It may not have been pretty, but it proved effective enough.

The build-up to the trip to McDiarmid Park was dominated by the talk of spies in the camp as tensions rose throughout the week.

After Steven MacLean reacted to Caixinha comparing the Saints’ style to Morton, Tommy Wright hit back at the Portuguese’s claim that he knew Rangers’ line-up before their meeting here in May as he labelled his Ibrox counterpart ‘paranoid’.

It added an extra intrigue to a crucial Premiership clash and there was no handshake on the touchline as the teams prepared to get the action underway.

Both the changes that Caixinha made were expected ones as Bruno Alves returned after his injury lay-off and took the place of Ross McCrorie, while Jason Holt partnered Graham Dorrans in the middle of the park as Ryan Jack served his suspension for being sent off at Accies.

The Portuguese also handed his compatriot Alves the armband for the night but there once again no place for striker Kenny Miller as he missed out despite being fit to play.

Caixinha insisted during the week that there was no issue with the 37-year-old after he was dropped from the squad for the trip to the SuperSeal Stadium last month.

Despite returning to the first team fold during the international break, Miller again had to watch the action unfold from afar as the man that has taken his place in the team got his third and fourth goals in Light Blue.

Rangers had created little in the opening stages, with a long-range effort from Josh Windass as close as they had come to breaking the deadlock.

But Pena was in the right place at the right time to give Caixinha’s side the lead after St Johnstone had failed to make the most of their spells of pressure.

Striker Graham Cummins should have put the hosts ahead when he burst clear of Alves but he couldn’t beat Wes Foderingham as the Gers keeper tipped his shot to safety. Just five minutes later, the miss would prove to be even more costly.

A whipped cross from James Tavernier was just too high for Alfredo Morelos to connect with but Pena was on hand behind the Colombian forward.

On another night of heavy touches and misplaced passes at times, the midfielder did well to divert the ball into the roof of Alan Mannus’ net and give Rangers a crucial lead.

It was an advantage that was never seriously under threat until the closing minutes of the half as Caixinha’s side failed to clear a Stefan Scougall corner. Cummins couldn’t capitalise, though, as he hooked a shot over Foderingham’s bar.

It had been a scrappy affair as neither side showed any real quality on the ball for a prolonged spell. It was certainly competitive, though.

That pattern continued after the break and it was Rangers that had the clearest chances early on as Pena pulled a low shot just wide after good work from Tavernier and Daniel Candeias down the right flank.

Just seconds later, Morelos’ shot was blocked by Steven Anderson as the striker looked to get back on the score sheet after firing blanks against Partick Thistle, Celtic and Hamilton.

Rangers needed the second goal to ease any nerves in their ranks but St Johnstone continued to cause Caixinha’s side problems.

The Gers stood firm to repel a series of corners, a sequence that included a brief skirmish in the box, as the Saints’ pressure came to nothing in the end.

With 19 minutes left, the task got even tougher for Wright’s side as Steven Anderson was shown a second yellow card for a foul on Morelos. Soon, the game was beyond St Johnstone.

It was Tavernier and Pena that did the damage once again, the right-back putting a teasing cross into the area and the Mexican nodding it into the net. Pena remains a much maligned figure in some quarters, but his impact here was decisive for Rangers.

He received a warm round of applause from the travelling Light Blues support when he was replaced by McCrorie with just minutes remaining. It was a reward for his efforts, and a sign that Caixinha was happy with his lot.

There was still time for the Gers fans to roar once more. Dorrans was denied by the woodwork before Pena made way and when Rangers attacked again he made no mistake as he beat Mannus with a clinical finish after being picked out by Holt.

Three goals earned Rangers three points. Now they need to make it three-in-a-row at Hampden.