As the clock ticked beyond 5pm on deadline day just over two months ago, Rovers were still busy working on two deals.

They had missed out on a couple of midfielders earlier in the day, but it was in defence that last minute deals were being pushed through.

Eventually, at 8.30pm, Greg Cunningham’s move from Cardiff City on a season-long loan deal was confirmed. It wasn’t until the next morning that Charlie Mulgrew’s loan switch to Wigan was rubber-stamped and announced by both clubs.

For the club captain to leave, seven days after leading the side out on the opening day against Charlton, in which he played 90 minutes, came as something of a surprise.

But even with Darragh Lenihan ruled out, Mulgrew had found himself behind Tosin Adarabioyo and the returning Derrick Williams for that weekend’s trip to Fulham.

Mulgrew can't be recalled until January, as per current loan rules, but were he at the club, could you see beyond Adarabioyo and Williams starting against Huddersfield? The more likely scenario would be the same back four that started at Craven Cottage.

So came the mutually agreed deal that Rovers would allow the 33-year-old, just one short of a century of league appearances for the club and still with two years left to run on the deal signed in November, to join their Championship rivals.

Conspiracy theories were aired by some, but it became clear that when all Rovers’ central defenders were fit, with Cunningham’s arrival allowing Williams to focus on his more preferred centre back role, that Mulgrew found himself out of the picture.

The majority of fans, particularly as time has wore on, have agreed (or at worst come to terms) with the decision to allow Mulgrew to leave, a situation that seems to have worked out well for both parties with the Scotland international getting regular game-time at the DW Stadium, and prior to the QPR defeat, Rovers having shown improvements in defence.

But Rovers' central defenders staying fit has been something of a problem in recent times, with three missing at the same time between February and April where they picked up four points from 11 games.

Injuries to Lenihan and Cunningham compounded a disappointing end to the five game block between the September and October international breaks.

When Lenihan is fit, he plays. Unfortunately, he is no stranger to missing games, he’s started only 69 of Tony Mowbray’s 108 league matches in charge.

Williams struggled for fitness last year, enduring niggling injuries throughout the campaign that restricted him to just 24 starts, and is new to playing continued games in central defence.

Adarabioyo has already shown a slight vulnerability having not been in the squad for six of Rovers’ 11 matches so far.

Behind that, Rovers allowed three of their fledgling prospects, Scott Wharton, Matty Platt and Tyler Magloire, all in need of game-time to leave on loan.

Other options for more Mowbray include Ryan Nyambe, a player the boss has hinted, despite previously suggesting otherwise, could fill in as a centre back given how well he performed in the Africa Cup of Nations for Namibia, and Under-23s captain Joe Grayson.

But injury blows to Lenihan and Cunningham are arguably two players they could least afford to lease. Even with the two injuries, Rovers aren’t necessarily depleted in options, but more so in quality. 

Mowbray has often referred to the plethora of centre halves he had at the club when he arrived in 2017. Added to Mulgrew and Lenihan were Elliott Ward, Gordon Greer, Wes Brown and Tommie Hoban.

Three of those were in their veteran years, Ward leaving in the early stages of the 2017/18 promotion campaign after the arrival of Downing, while Greer and Brown were released after relegation, while Hoban returned to Watford after his loan spell.

It was raised during a fans’ forum meeting last year about the level of investment in the defensive areas in recent years. Lenihan and Nyambe were Academy products, Williams and Amari’i Bell signed for around £250,000 and £300,000 respectively, with other recent signings including Jack Rodwell, Paul Downing, Paul Caddis and Mulgrew on free transfers, while Adarabioyo is on loan.

Further back come are the Olsson twins and Adam Henley (Academy), Matt Kilgallon and Tommy Spurr (both free tranfers), the list goes on.

During Gary Bowyer’s reign, he relied largely on an Academy product in Grant Hanley, and Shane Duffy, a player who is the rarity among Rovers’ recent defenders, given he commanded a fee pushing the seven-figure mark.

While transfer fees don’t always bring success, and attacking players do generally attract larger numbers, it is an interesting topic of debate.

Whatever this season brought, Rovers were always going to have to reinvest, or at least reassess their defensive line next season.

Mulgrew would be returning from a year out on loan, loan deals for Christian Walton, Adarabioyo and Cunningham would draw to an end, and the club would need to decide what next for their host of young centre halves.

There will be scrutiny on Rovers this season, given the post-promotion year was something of a free-hit, and seeing whether they can improve on a defensive record that saw them ship 69 goals last season, in which their 48 away from home was a league high, will be among the factors taken in to consideration.

They do have numbers to withstand the injuries to Lenihan and Cunningham. Whether they have the quality to do so, will be tested in the next few weeks.