The January transfer window ended up being a busy one for Middlesbrough as six new players arrived, while six left - with a seventh departee in Lukas Engel expected to be announced in due course.

While the business represents another huge push from Boro after securing big deals and eye catching moves for the likes of Mark Travers, Morgan Whittaker and Samuel Iling-Junior, there is one major concern that was only exacerbated by Monday evening’s defeat to Sunderland. A continuation of so many of the team’s flaws this season, their defensive frailties and weak underbelly were on show once again.

It’s for that exact reason that so many fans were hoping to see Boro sign a new combative midfielder, while also improving their defensive line. In that regard, the only business done was making George Edmundson’s loan deal a permanent, while it’s fair to say Ryan Giles’s arrival is more about what he can offer Boro in attack, rather than defence.

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With Matt Clarke leaving for Derby County without a replacement, it leaves many understandably concerned about Boro’s defensive depth too. With only three senior centre-backs now, it leaves Boro only one or two defensive injuries away from a bit of a crisis - a repeat of the scenario which saw them sign Edmundson unexpectedly in the summer in the first place.

In terms of not replacing Clarke, it was believed to have been a decision taken due to Michael Carrick’s faith in the options he has. Clarke was allowed to leave after falling to fourth in the pecking order. Despite the obvious defensive qualities he’d shown in the last 12 months, he didn’t ever fit the way Carrick wants to play and, frustrated with his game-time, was allowed to leave.

While Boro’s recruitment team ultimately had defensive options they were willing to explore for Carrick in the final week of the transfer window, the Boro boss ended up ruling out a new addition at the back, simply stating in his press conference on Friday when asked, ‘nah, we’ll be alright’.

As for right-back and centre midfield, they were both positions that Boro did take a closer look at before the window closed - more so because of interest from elsewhere in Anfernee Dijksteel and Dan Barlaser. In the case of both, it would have made business sense to allow them to go, but only if replacements were found.

Boro certainly pushed hard for a midfielder. Negotiations went on for some time with French side Rennes to try and structure a deal that was financially viable for Boro to bring Glen Kamara in on loan. In the end, they suffered a blow when mega-rich Saudi club Al-Shabab joined the race and blew them away financially.

On Deadline Day, two more midfield names emerged. Will Smallbone links ended up being late. Boro asked about the Southampton midfielder the week before Monday’s deadline. However, the midfielder, who has just returned from injury, preferred to stay and fight for his place in the Premier League, rather than drop down to the Championship.

And very late on, with Boro by now reluctant to add any more loan players after taking their squad up to five (the maximum number you can name in any given match-day squad), they made an enquiry to Liverpool about Tyler Morton, who starred on loan at Hull City last term. With the Reds demanding a fee worth over £10m with bonus payments and add-ons, it was an immediate non-starter for Boro and they decided not to allow Barlaser to leave as a result.

As for right-back, with Dijksteel entering the final 12 months of his contract, Millwall’s interest gave Boro a decision to make. Again, there were options explored and available to Boro. But in the end, the decision was taken to not add further disruption to the squad, with already so much change, unusually, in a January transfer window.

Dijksteel, who is currently out through injury, has been Boro’s best right-back this season. Luke Ayling’s form is a bigger concern right now. Amd with that in mind, keeping Dijksteel appeared the least risky option for Boro in the middle of a season where they are still more than in the mix for a play-off spot.