Foster knows what Old Firm defeat feels like, now he's out to rub salt on old club Rangers' wounds with St Johnstone

The 31-year-old was on the wrong end of results against Celtic in two spells with Rangers so he knows Mark Warburton’s players will be hurting.

But now the St Johnstone full-back is hoping to rub salt in Rangers wounds and pull away from the fifth-placed Ibrox club.

“We’ll try and disrupt the flow of their game and not let them settle into a rhythm," Foster said. “Most importantly, you need to stay in the game and keep it tight for the first 25 minutes. The crowd will start to get more anxious.

“There’s a massive expectation on Rangers. They’re expected to win every home game and that won’t change for this one.

“Their fans will be expecting a response to the Old Firm defeat. I know it was only 1-0 but when you lose to your biggest rivals it is never nice.

“The crowd will be expecting a reaction and so will we. In terms of fatigue we’ll be the same as Rangers because we both played on Sunday. I’m not going to lie, I was hoping for extra-time.

“They might be on a bit of a downer and an Old Firm semi-final will be mentally draining.

“There are so many highs and lows in games like that and they were close to getting to a final. They held out until something like the 87th minute.

“Mentally and physically they’ll have put a lot into the game and we’ll be hoping there’s a bit of a hangover.”

Tommy Wright’s Perth team moved past Rangers in the league standings on Sunday with a 2-1 derby win over Dundee.

And summer arrival Foster isn’t surprised Saints are again mixing it in the top six.

“It’s all credit to the manager and the players who were here before me that we’ve been so consistent over the years," he added.

“It’s been very easy for me to fit in. It’s great that we’re trying to keep on the coat-tails of these big clubs.

“There are clubs who have much bigger budgets than we do. For St Johnstone to be up in third, fourth or fifth is a great achievement.”

Foster is looking forward to an Ibrox return as the games come thick and fast. And he expects Ibrox manager Warburton to their usual attacking style.

“They’re at home and are expected to win the game. They are very fluid when they play their normal formation and keep the ball very well. So I think they will change back.

“There might be a few personnel changes but it will probably be 4-3-3, which it has been for every game bar Sunday’s.

“We need to try and disrupt them when they’re in possession. You have to try and flood the midfield and not let them make their forward passes.

“Obviously they have a lot of threats up front and coming from full-back with Tavernier on one side and Wallace on the other.”

Saints have clocked up four wins in their last six games and survived a late scare to claim all three points against Dundee.

“I thought we played really well. It was incredibly one-sided,” said Foster. “With the penalty late on the last few minutes were a bit nervy but if we hadn’t taken three points from that game it would have been a travesty because we were so dominant.

“We got into a lot of good areas and maybe could have been even more clinical to make it more comfortable. But it was a great team performance and sets us up nicely for our next game.

“We’ve got 17 points already. If we maintain that we’d be sitting on 51 points at the split which would be a great return.

“We’re going into this game thinking that if we play the way we can, and the way we played against Dundee, we can get something from it.

“Everyone in the team is willing to help out their mate. If I make a mistake, nine times out 10 Steven Anderson is there to mop it up. I try and do the same for him, and it’s the case all over the pitch.

“Sometimes people can end up in different positions but we keep our shape and make it difficult for teams to break us down.

“That’s been the hallmark of St Johnstone for the last four or five seasons.”