DARREN Jackson is musing on the theme of whether footballers automatically become better players when they move to one of the Old Firm clubs.

The discussion is, of course, brought on by the sudden lionisation of Stuart Armstrong and Gary Mackay-Steven since their deadline day departures to Celtic, although both former United players are cup-tied and unavailable for today's Scottish Cup quarter final meeting between the two teams.

While some of Rangers' acquisitions from provincial clubs in recent seasons have appeared to exhibit precisely the opposite effect, the Dundee United coach - who spent a couple of seasons at Parkhead after moving from Hibs in 1997 - reckons he in fact might just be the exception that proves the rule.

"It didn't happen with me ... I couldn't get a game when I went to Celtic!" said Jackson, only half jokingly. "No, it just tends to happen after you move that you get into the Scotland squad. But I totally understand that situation, because you are playing at a higher level, you are playing against Inter Milan in Europe and that helps take you into the international team. It shows you how good Stuart and Gary are that they have gone in there to Celtic and been main players right away, a huge part of their team. But no-one had to tell us that."

A quirk of the Scottish football calendar means that United must play Celtic three times in three different competitions in three successive weeks. While Armstrong and Mackay-Steven won't be able to feature in the first two, today's Scottish Cup quarter final at Tannadice and next Sunday's League Cup final at Hampden, the overturning of Nadir Ciftci's ban means the Turk -already banned for the League Cup final - can at least play today. Playing the same side three times in such a short period can cause problems but Jackson is sanguine about it all.

"You play the first one, see what the result is, what the performance is like, what injuries there are," he said. "You can't prepare for the second one until the first one's over. They're all different - a quarter, a final and a league game. I'm not saying the league game isn't important but you can't help thinking about the cup games."

The Scottish Cup was the one piece of silverware that eluded Jackson during his career. After an injury time goal prolonged it into extra time, his involvement in the 1991 showpiece at Hampden, the so-called family final against Motherwell, didn't end well. "I got called into the ref's room and got a red card afterwards," he recalls. "What for? Shaking the ref's hand and saying he had a good game!"

At least he has his memories of winning the title with Celtic, defying Rangers' pursuit of ten in a row, to sustain him - a period which led to him representing Scotland at France 98. He feels there are certain parallels between Ronny Deila and the way Wim Jansen made a success of himself following a shaky start. "We lost the first couple of games, so it shows it takes some time," said Jackson. "But they're doing very well just now, playing a lot of good football, and Stuart and Gaz have also given them a massive lift."

Some of United's fans were demoralised by the sale of the club's two most prized assets to their main rival this season, but Jackson feels they must have faith in the system. "The gaffer has a picture in mind," he said. "When boys leave there are others that come through. It is the structure of every club really because everyone needs to sell. To a lesser extent even Celtic."

Along with the likes of Ryan Dow and Charlie Telfer, one man hoping to make the step up is Blair Spittal. Released by Rangers as a kid, Spittal is hoping to follow Andrew Robertson in using Queen's Park as a stepping stone. "The attraction of going to Celtic or Rangers when you're younger is massive and I'm glad I experienced it," he said. "I was 13 when I went there, so I was buzzing initially, but the older you get, you realise you need to be playing football every week, so leaving was probably best for me. Charlie [Telfer] was in my team - and he's obviously here now - and I played with Andy Murdoch, who's coming through now."

As for those social media rumours about Jackie McNamara leaving the club, Jackson has satisfied himself that there is nothing in them. "That's what it was - a rumour," said Jackson. "It's false. Jackie's here for the long term. He's only started things here. He's not bringing players through the system for the next manager. He's bringing them through for us."