​Cammy Devlin, Nicolas Raskin, Dan Neil and Connor Barron could all be vying for one defensive midfielder role [SNS]Cammy Devlin could not hide a wry smile when asked if he was confident of being a surefire starter for Rangers following his summer switch from last season’s title rivals, Heart of Midlothian.If the Australia 28-year-old did not know it before his return from the World Cup, his first couple of training sessions were a reminder of the plethora of players already competing for the central midfield berths with the Ibrox side.And media questions at his first public press conference also emphasised the number of players in his position still being linked with a possible summer transfer to the Scottish Premiership club.New manager Derek McInnes hopes to complete a couple more deals – not necessarily midfielders, though – before they start their season away to Dundee United in the top flight on Friday evening.So who are Devlin’s rivals in the Ibrox engine room?McInnes teases Rangers signing within 48 hoursWho has your Premiership club brought in & let go this summer?Devlin opens up on ‘too stressful’ Hearts exit for RangersSurplus of defensive playmakers?Three of Rangers’ seven summer signings – and none of their 11 departures – are central midfielders.Yet they already had six on their books – nine if you include three who were out on loan.Considering they are attacking midfielders, you can discount Thelo Aasgaard, who has just been to the World Cup with Norway, and Nedim Bajrami, who has failed to become a regular starter in his two years at Ibrox, as competition for the more defensively minded Devlin.Likewise Jose Cifuentes, Lyall Cameron and 20-year-old Paul Nsio, considering they have returned from Toronto, Aberdeen and Raith Rovers, respectively, without having suggested they are ready to make the step up.Ivory Coast international Mohamed Diomande, whose form dipped in his second full season at Ibrox, is more a box-to-box man.Meanwhile, Nicolas Raskin has looked more effective pushing forward for Rangers despite preferring to play just in front of the defence.It was, though, in that latter role that the Belgium international received rave reviews at the World Cup, making it ever more likely that Rangers will look to cash in this summer on a player who has expressed his desire to move to a top-five league.Given Raskin’s anticipated exit, it was no surprise McInnes would look to snap up Devlin, given the Australian was a key player in their title challenge together with Hearts – especially as he was available for free.However, Rangers have also added two more defensive midfielders – Dan Neil, who was out of contract with Sunderland, and Vanja Dragojevic, purchased from Partizan, where he was captain at the age of just 20.That is before considering two more defensive midfielders already on Rangers’ books.Scotland cap Connor Barron must have been relishing the arrival of his former Aberdeen manager as he seeks more regular starts, whil