IF Rangers defeat Celtic at Parkhead tomorrow lunchtime, in one sense Brendan Rodgers will only have himself to blame.

Not necessarily because the Ladbrokes Premiership Manager of the Month for August will have misjudged his line-ups, tactics or team talk, but because of the encouragement he provided in the formative stages of their careers to certain key members of the Ibrox party who will turn up at Parkhead for the first league encounter between these two sides for four years.

It is well documented that Rodgers and Mark Warburton forged a friendship at Watford while the former was manager and the latter was academy manager.

Read more: Rodgers: Griffiths would be a big loss for Celtic but others can fill the void against RangersThe Herald: Celtic manager Brendan Rodgers is presented with the Ladbrokes Premiership Manager of the Month award for August. Picture: SNS

While that arrangement lasted just seven months, and the closeness of the pair can be exaggerated, Rodgers also dovetailed with director of football Frank McParland, an acquaintance which would be renewed when the two men linked up again at Liverpool.

As for the Ibrox side's current raft of players, it was Rodgers who inherited an 18-year-old midfielder called Rob Kiernan from Warburton's youth team and gave him his senior debut as a central defender.

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And Rodgers again who gave a prodigious 17-year-old Scouser called Jordan Rossiter his debut in a League Cup tie against Middlesbrough, the midfielder taking his opportunity by becoming the second youngest man after Michael Owen to score a goal for Liverpool. With friends like these who needs enemies, some might say, but the Celtic manager's footprint on this Rangers side should not be underestimated.

“We haven’t spoken much," says Rodgers on the topic of his old academy director Warburton. "I know what happens when you are friends with someone and then all of a sudden you are a best friend. Mark and I worked together for seven months and I probably knew others better than him when I was there then when I left to go to Reading we had sporadic contact. When he was at Brentford and I was at Liverpool he would ring up, but we are not going out for dinner or anything like that.

"But he is a good guy and I know some of the other guys that work with him like Frank McParland who is a good fella too," added the 43-year-old. "I have a huge respect for managers who work and operate in the game and he [Warburton] is one of them. I think he has done an excellent job. He did a really good job in his first year - he turned things around and got them promoted. Obviously at this level they haven’t lost but he is now seeing what the expectation of being at a club like Rangers means.

"They brought in a lot of players. That always takes time if you are bringing in 9, 10 players, it is all very difficult. But I look forward to having a drink with him after the game – we’ll catch our breath probably."

While Kiernan, along with the entirety of the Rangers central defence, has been subjected to some not entirely undeserved criticism, it should be pointed out that the centre half produced a fine performance in last April's Scottish Cup semi final.

“Rob Kiernan was a young boy who was a midfield player when I was at Watford," said Rodgers. "He wasn’t getting a lot of chances in the youth and reserve teams because there were other players ahead of him. But because he had good size and stature I thought he could play number two centre-half. I thought he would need a dominant one beside him but he could play football and he could serve the ball. I watched his development as he came up to Scotland [Kilmarnock] and then went to Wigan. Now he finds himself at Rangers but he was a good boy and he is developing well.

"Young Jordan was always a terrific young player that came through the system at Liverpool," added the Celtic manager. "It is always great to have a young, local lad come through the system there and I saw lots of items in his game that I really liked – he was competitive, and a star for the youth England teams. He had an older head on his shoulders and he wasn’t frightened to tell an older professional what to do and what not to do and that is always a good sign when they’re young.

"I wanted to test him when we were playing Middlesbrough and they were at the top of the Championship which is a very competitive level and he did not look out of place and scored a goal. Unfortunately there were a lot of good players which made it hard for him and obviously he wanted to leave to play regular football. But again, a really good boy who was dedicated to his profession and I really liked him a lot."

Rossiter, Kiernan, McParland, Warburton: all these echoes of the Celtic manager's past life will come back into view tomorrow when certain members of the Rangers squad will hope to bite the hand which used to feed them.