After months of rumours it all comes down to this, transfer deadline day is here.Managers, chairmen and agents will be glued to their phones deep into the night as they aim to complete any last-minute business just in time.Despite having months to perfect their playing squads for the first half of the campaign at least, you just can’t account for a late bid for your best player or the prospect of bringing in a big name who was previously out of reach.You can keep across all the deadline day moves on stv.tv/sport as well as the STV News app. Here’s a guide to some of the main stories to look out for.Gary Mackay-Steven and Brendan Rodgers SNSThere’s little doubt the champions have significantly strengthened their playing pool under Brendan Rodgers this summer but could they do one more deal?Defender Cristian Gamboa became the sixth arrival under the new boss but the Northern Irishman has made little secret of his desire for a creative midfielder. With Champions League football secured, a marquee playmaker could help make the difference against Barcelona, Man City and Borussia Moenchengladbach.Any newcomer could have a significant impact on Kris Commons’ hopes of regaining his place in the team while winger Gary Mackay-Steven has been linked with a loan move away as he steps up his recovery from injury. Jozo Simunovic could complete his move to Torino where he would team up with England goalkeeper Joe Hart.Phillippe Senderos spent one week training with Rangers.Mark Warburton has spent the summer trying to fix the glaring weakness in his Rangers squad – the centre of their defence.Early Premiership performances have only heightened the need to strengthen this area of the team but talks with Steven Taylor, Adrian Mariappa and Joleon Lescott all proved fruitless while Phillipe Senderos appears to be the fall back option.The former Arsenal man remains a free agent so this one could run past Wednesday’s deadline but supporters will want to see some sign of progress with a trip to Celtic Park looming large on the horizon.Another cause for concern comes in the form of Martyn Waghorn’s contract impasse. Currently sidelined with a hamstring injury, the forward has been mentioned as a target for Bristol City following the sale of Jonathan Kodjia to Aston Villa.January target Toumani Diagouraga continues to be linked with a reunion with Warburton after falling foul of another change of management at Leeds. Signed by Steve Evans in the last transfer window, the former Brentford man is surplus to requirements under Garry Monk.Marvin Johnson has asked to leave Motherwell. SNS GroupHe’s been Motherwell’s main man with four goals so far this term and Marvin Johnson’s performances have made plenty of clubs sit up and take notice.After turning down offers from Oxford United, fans of the Steelmen may have been forgiven for thinking they had done enough to keep hold of their prize asset but the 25-year-old decided to force the issue by handing in a transfer request earlier this week.A firm statement on the club’s website outlined their determination to keep hold of Johnson unless a club meets their asking price. The next 24 hours could have a huge impact on Motherwell’s season.Ryan Jack has been ruled out of action with a knee injury. SNS GroupDerek McInnes has put plenty of faith in Ryan Jack and it looked as if the midfielder was starting to repay him with some fine early season displays.Unfortunately a knee injury has ruled the 24-year-old out for several weeks with an operation required, leaving the Dons extremely short in the middle of the park. Barry Robson and Willo Flood are no longer part of the squad while Graeme Shinnie’s move from left back to a central role continues to be the source of fierce debate.Kenny McLean and Craig Storrie represent McInnes’ other current options and so he may choose to delve into the transfer market for a quick fix.Prince Buaben and Juanma have been linked with moves away from Tynecastle. SNSHaving faced criticism for some of their transfer dealings last term, this was always going to be a crucial transfer window for Hearts. Aiming to build on their third place finish, Robbie Neilson and Craig Levein have trusted their judgement and brought in a mix of Scottish players and recruits from further afield.Keeping hold of Scotland international Callum Paterson will be the priority while moving a few fringe players on will also be high on the agenda. Juanma Delgado and Juwon Oshaniwa have yet to feature this season having fallen out of favour while Prince Buaben has held talks with Ross County over a transfer to Dingwall.