THERE has been a lot of discussion over the last week or so about whether Sunderland should re-sign Jermain Defoe. Come the end of the season, though, it might well be their January transfer business at the other end of the field that is the decisive factor in determining what league the club are playing in next season.

Having identified the need for a physically-imposing centre-half, with proven capabilities in England’s top three divisions and leadership qualities that would enable him to slot straight in at the heart of a back three, Lee Johnson moved decisively last week to sign 31-year-old Danny Batth on an 18-month deal.

One game into Batth’s Sunderland career, and the decision to recruit him already looks an extremely astute one. The Black Cats were not at their best as they edged out Portsmouth to return to the automatic-promotion places, but a first clean sheet in four matches meant that, for once, they didn’t have to be.

Leading through Elliot Embleton’s 40th-minute strike, Sunderland successfully contained a hard-working Portsmouth side that enjoyed plenty of possession, with Batth leading the way alongside Tom Flanagan and Callum Doyle.

One moment in the second half summed up his performance as he eased Tyler Walker out of the way, leaving the Portmsouth forward pleading for a free-kick while sitting on his backside, before striding upfield towards the halfway line. That might not be the beautiful game Johnson aspires to deliver, but it is something Sunderland have been crying out for, for much of the season.

“I thought he (Batth) was brilliant,” said the Black Cats boss. “I’m down there low, and I can hear everything he’s saying. He’s got that physicality and he takes the emphasis off Flanno (Flanagan) having to be physical and be the dominant one.

“I thought he was good in possession, he made a couple of long deliveries, and there were a couple of big moments where he won physical duels in the middle of the pitch and managed to use his physicality and his upper body strength to allow somebody else to come in and take the ball.

“We need to win all types of games. It’s something I recognised early on in the season, but that we maybe didn’t address early enough. I think the signing of Danny has addressed that and given us that dominance.”

The point about winning ‘all types of games’ is a relevant one, especially given the state of the Stadium of Light pitch, which continues to regress and now actively discourages the kind of slick, neat passing football Johnson has made his trademark throughout his managerial career.

Try to play too much football on Sunderland’s rutted home turf at the moment, and you will come unstuck, as was the case when Portsmouth tried to play out from the back in build-up to the Black Cats’ goal.

Sean Raggett was robbed of possession deep in his own half, Ross Stewart laid the ball off the Embleton, and the midfielder stroked a measured finish into the bottom corner.

In the absence of Alex Pritchard, who along with Bailey Wright has suffered a calf injury, there was a greater emphasis on Embleton providing a goalscoring presence behind Stewart, and while the 22-year-old might not have been at his free-flowing, creative best, he held his nerve when it mattered shortly before the interval.

This time last year, Johnson was making the difficult decision to send Embleton to Blackpool on loan. The move did not really work from a Sunderland perspective, with the North-Easterner helping to propel the Seasiders to the Championship while his permanent employers floundered in the play-offs, but in terms of aiding Embleton’s personal development, it has proved a wise decision.

“Elliot is a complex character, a real talent,” said Johnson. “He works hard, a really good trainer, up there with the top two or three every day. I think he can grow as a personality on and off the pitch, and that will only enhance what he does really well.

“His technical quality on both feet, his ability to turn on a sixpence and link up, is excellent because he has a really high football IQ.

"He’s passionate about the club which is something we love, and we want to nurture and channel that.

“I never had any doubts. Loaning him out came back to bite us on the backside, but it was the right thing to do for him and for us, to develop him.”

Embleton’s goal came at the end of a first half that Sunderland gradually began to dominate after a slow start, and preceded a second period that saw the Black Cats establish a reasonably high degree of control without ever really looking like they were going to extend their one-goal advantage.

Portsmouth did not look like equalising either, although the visitors wasted a golden opportunity with one minute left when substitute George Hirst headed over from a corner.

“It definitely wasn’t a classic, but it was well fought,” added Johnson. “Look at how many players we’ve got out of the team – in the last ten or 12 games of the season, we could be really special if we get them back.”