One in, one out. Sunderland's deadline day business was all about defenders.
But when the transfer window closed, the gaping hole in their squad remained unfilled. Sunderland went into January in desperate need of at least one additional striker, signed one, lost their main man to a serious injury, and found themselves worse off than when they started.
No wonder Sunderland fans were left gnashing their teeth as the clock chimed 11pm. When Everton recalled Ellis Simms from his loan spell at the beginning of the month, the Black Cats desperately needed to bring in a replacement as competition and cover for their talisman and leading scorer Ross Stewart who was their only remaining out-and-and centre-forward.
READ MORE: Sunderland's Bailey Wright explains the reason behind his deadline day exit to join Rotherham United
Joe Gelhardt answered the call on Friday, signing on loan from Leeds United for the rest of the season, only for Stewart to suffer what is almost certainly a season-ending Achilles injury less than 24 hours later in Sunderland's FA Cup fourth round tie at Fulham. Now Gelhardt is the only central striker available to Tony Mowbray and, while Stewart has 40 goals in 81 outings since moving to England, 20-year-old Gelhardt has scored only three times in 62 senior appearances (albeit the majority of those have come as a substitute).
Sunderland's sporting director Kristjaan Speakman worked to bring in another striker but ultimately came up empty-handed and at no stage on deadline day did a deal seem close. Their best hope seemed to lie in Everton allowing Simms to return, but clearly new Toffees boss Sean Dyche decided that, where strikers are concerned, he needed all hands on deck for the Merseysiders' relegation fight.
Mowbray had to 'find a way', as he repeatedly put it, when both Stewart and Simms were out for lengthy spells earlier in the season, operating with different systems and false nines with the likes of Alex Pritchard, Jack Clarke, and Amad, operating through the middle at different times, and - unless Sunderland add a free agent - if anything happens to Gelhardt he will find himself needing to make do and mend once again. As for the deals that were done on deadline day, they had been widely trailed.
Young Everton centre-back Joe Anderson completed his move to Wearside in the morning for an undisclosed fee, signing an initial three-and-a-half year deal. And that cleared the way for Australia international Bailey Wright to head out in search of regular football after growing frustrated at being a bit-part player in the first half of the season.
His exit was expected with only his destination in doubt, and in the end he joined Championship strugglers Rotherham United on loan for the remainder of the campaign. The rest of Sunderland's January transfer business was done ahead of time.
Three of their four new signings - midfielder Pierre Ekwah from West Ham, forward Isaac Lihadji from Lille, and Gelhardt - were already in situ when deadline day dawned, with only Anderson to follow. As for the outgoings, at senior level there have only been three this month - four, if you count Simms' exit.
Simms went at the beginning of the month, while midfielder Jay Matete joined Plymouth on loan in the first week of the window, Leon Dajaku joined Swiss side FC St Gallen last week, and finally there was Wright. Ekwah will fill the gap in the squad left by Matete, Gelhardt is a replacement for Simms, and, while Anderson does not have the experience that Wright provided, Sunderland were overstocked on centre-backs and the new man will be happy to compete for a place in the side whereas a seasoned pro such as Wright needed to play every week.
So, all other things being equal, that would have added up to a decent enough January window as far as Sunderland were concerned, with the squad looking as strong, if not stronger, than it had been going into the month. But all things were not equal.
Because during January Sunderland also lost two of their key men to serious injuries, with influential midfielder and captain Corry Evans suffering a ruptured cruciate ligament which will rule him out for the rest of the season even before Stewart's Achilles tear. Take those two players out of the pool and the squad is weaker now than it was on January 1.
In midfield, with Dan Neil, Edouard Michut, Abdoullah Ba, Pritchard, and others along now with Ekwah, Sunderland should have enough strength in depth to cover for Evans. But Sunderland's failure to land a striker to replace Stewart has left a huge void.
Last season, Sunderland played Russian roulette with their promotion chances when they were left dependent on Stewart for goals as their then loanee Nathan Broadhead was ruled out for months with a hamstring injury while their January deadline day move to bring 39-year-old Jermain Defoe back to Wearside for one last dance ended in embarrassment all round as he stumbled around like a man with two left feet before hanging up his boots just seven weeks later. Thankfully, Stewart stayed fit and scoring goals until Broadhead recovered to rejoin the fight in April, and between them they powered the side to promotion.
This season, there are no such promotion expectations on Wearside but they still have a chance of making the play-offs - they are currently just a point outside the top six. If Gelhardt gets injured, or if he does not deliver the goals needed, Sunderland could easily slip back into midtable.
Given this is Sunderland's first season back in the Championship, midtable would still be a very good platform on which to build. But there would be a nagging sense of what might have been if only Stewart had stayed fit.
Or if another striker had been signed in January.