Boasting one of the best defences in the second tier of English football, Swansea City's back line have already kept 10 clean sheets in the league this season.
But, with the news that Garry Monk could now be out for up to three weeks with a calf strain after limping off in Swansea's 1-0 victory at the weekend and Alan Tate missing out through suspension, Brendan Rodgers faces two big problems ahead of Saturday's fixture at the Keepmoat stadium.
With only two of the reliable back four of recent weeks available the Swans will have to quickly adjust without the absentees.
The obvious player to step in for Tate this weekend will be Neil Taylor - the youngster has been impressive and has quickly adjusted to life in the Championship since making the leap from Blue Square side Wrexham in the summer.
Despite still lacking experience at this level, Taylor has made the most of his opportunity to come in at full back as Tate has had to move into central defence to partner Williams on a few occasions this season, due to Monk seemingly been plagued with injury over recent weeks.
The only like for like replacement available to start in place of skipper Garry Monk this Saturday would be Albert Serran, which would see the Spaniard make only his fourth league start of the campaign. Starting alongside these two players means Ashley Williams will need to use all his experience as he is set to make his 108th consecutive league appearance.
Against a Donny front line who have been involved in some high scoring contests over recent weeks including a 3-2 victory over Pompey, the Swans will have their work cut out to keep their fourth consecutive clean sheet on the road.
In order to combat this issue, Rodgers may opt for a more defensive line up which could see both Allen and Gower start in a deep role sitting just in front of our back four and have Pratley pushing forward in support of the two wide men and lone striker Dobbie, who should return to the starting line up after coming off the bench on the weekend and looking dangerous, despite being on the pitch less than 20 minutes.
Disclaimer: The views in this article are that of the writer and may not replicate those of the Professional Footballers' Association.