Former Celtic manager Martin O’Neill believes Rangers face a major test at Hampden on Sunday as he questioned their big-match mentality.

Rangers have not beaten their Glasgow rivals in five matches and failure to arrest that run in Sunday’s Scottish Cup semi-final will mean they finish the season without silverware.

Michael Beale will get the chance to reshape his squad in the summer after replacing Giovanni van Bronckhorst during the mid-season break but he already faces pressure after losing the Viaplay Cup final and falling 13 points behind Celtic in the cinch Premiership.

In a press conference arranged by Viaplay TV, O’Neill said: “Obviously Celtic have the upper hand at the moment. Victories give you that confidence and self-belief.

“I think Rangers have some decent players, but at big moments they just seem to falter. The last match it was 1-1, a simple headed clearance, they should have dealt with it and almost tried to keep the ball in play. The next thing Celtic are 2-1 in front.

“In big matches Celtic are flying and Rangers don’t seem to be able to nail them at all.

“It comes from results. Obviously the Old Firm matches are massively big. If you can’t win those games then of course confidence suffers greatly.

“So this is a big, big test for Rangers, a really big test for them.

“It’s amazing to say that. Not long ago they were contesting a Europa League final, a kick away from winning it.

“I had a lot of time for Van Bronckhorst as a person and a manager, and a player. I really felt for him, I genuinely did do, I thought it was tough that he lost his job. But, listen, if you are not winning football matches then you know the consequences.”

Celtic had not beaten Rangers in seven matches before O’Neill took over in the summer of 2000 and had only won four trophies in the previous 11 seasons.

O’Neill described Rangers as the “benchmark” but his revamped Celtic side proceeded to beat Dick Advocaat’s men 6-2 in his first Old Firm derby on their way to a domestic treble.

The shoe is on the other foot now and O’Neill knows from experience that Beale will feel the pressure to turn the tables.

The former Nottingham Forest and Northern Ireland midfielder said: “Absolutely, Celtic are the benchmark and Rangers have to get there. And they will have to get there sooner rather than later.

“When I came in, there was about a 20-point gap. If you thought about it realistically, you would want to try and close that gap as soon as possible and then try to take over.

“I got a bit of luck early on, won a couple of matches that we might have drawn even before we played Rangers.

“So by the time they hammered us at Ibrox in November-time, we had enough confidence from winning football matches.

“Rangers don’t have that to fall back on. In fairness to the manager who has come in, up until not so long ago they were matching Celtic in terms of league results but they weren’t making up any ground.

“That meant that the game against Celtic was massive, they had to win that game to close the gap. That hasn’t happened. So Celtic are very much the benchmark and Rangers have got to do something about it, and relatively quickly.

“You don’t get the time, absolutely. If I think back, I was trying to convince myself about closing the gap. I’m not sure that would have held for a great length of time. I might have been given a little bit of leeway early on, but eventually you are up here to win. The manager knows that anyway.”

:: Martin O’Neill was promoting Viaplay’s live and exclusive coverage of Rangers v Celtic on Sunday. Viaplay is offering a special limited-time offer for Scottish football fans available until Sunday only. Visit viaplay.com for more information.