The state of play with Sunderland's transfer targets and what they would bring

An early breakthrough saw Chris Coleman bring in the talented Jake Clarke-Salter to bolster his defence but since then the Black Cats have been frustrated in their attempts to add reinforcements.

The departures of Lewis Grabban and James Vaughan, as well as the early end to Mika's contract, has freed up a little room on the wage bill but also underlined the need to strengthen the forward line.

Sunderland are working on a number of deals and Coleman has remained optimistic. He has thus far been pleased with both the club's willingness to invest, albeit on a very limited scale, and also the response of players who have been largely keen to join in spite of the club's position in the league.

Coleman has been a victim of circumstance on two deals that he hoped would come to fruition and on which the Black Cats had made solid progress.

They were close to a deal for Burnley's Jonathan Walters, who was struggling for game time in the Premier League. The 34-year-old would have brought real presence to the front line and also the kind of strong personality Coleman is looking for, but the Irish international was forced to undergo keyhole surgery on his knee.

Coleman's other top striking target suffered a similar fate. Manchester City were keen to loan out 19-year-old Lukas Nmecha after the talented striker signed a new contract earlier in the month. He has been prolific in the youth development sides and Sunderland had hoped that they could complete a deal in time for the clash with Birmingham City next Tuesday. However, they have since learned of an injury to the forward that could keep him out for as long as a month.

It is not beyond the realms of possibility that they could revive their interest later in the month should they fail to secure other signings up front and Nmecha makes good progress in his recovery, but they will pursue other targets in the final week of the window.

Their main priority, as widely reported, is the Derby County striker Chris Martin.

Sunderland came close to completing a deal for the 29-year-old last Thursday night, and the broad agreement for a loan deal remains in place. With Reading still hovering and rumours of interest from Wolves gathering pace, concerns are clearly growing that the move will not come off.

Nuno's high-flying side are looking for cover up front after signing Valencia's Rafa Mir earlier in the month, and Martin's rich Championship experience would no doubt appeal.

For Sunderland, his experience would offer a welcome balance to their striking options. Josh Maja and Joel Asoro have both impressed and were superb against Hull City, but the club are well aware that players with such little experience are likely to be inconsistent and more crucially, an injury to either would leave the side badly underpowered.

Both will have a major role to play in the fight against the drop but Martin would offer a different dimension and give Coleman the option of a player with good poaching instincts but also real strength and ability with back to goal.

Sunderland struggled badly against the physical defences of both Middlesbrough and Cardiff City and variety is needed. Martin would offer it.

Initially, Martin's decision to fly to Dubai for warm weather training with the Rams was not seen as a decisive blow. A decision would be expected when they return later in the week and Sunderland have until Monday lunchtime to register any new player for the trip to St Andrews.

Echo readers polled on Tuesday unanimously agreed that the club should look elsewhere given Martin's indecision and apparent reluctance to make the switch to Wearside, an understandable stance given Grabban's premature departure this month.

The Black Cats will hope Martin is merely giving full thought to a big decision in his career and will settle on Wearside as the best option. Clearly, the longer the wait goes on the more Sunderland will be forced to consider other options.

The attacking department is the biggest cause for concern at the moment and likely to be the one that makes or breaks Sunderland's season. It remains the key focus and the area that a breakthrough would be most welcomed. Two additions would be a real boost to the mood on Wearside after the Hull City win.

There may well be one or two additions in other areas of the pitch.

Sunderland have a strong interest in Ben Marshall and are in talks with Wolves over a potential deal. The 26-year-old could play in the right wing-back position but is a natural winger who would offer Coleman more depth and a proven Championship option as the inside right in the 3-4-3 system he has regularly played since taking charge.

Aiden McGeady and Callum McManaman have struggled for form and not been able to offer a significant counter-attacking threat, something which the side clearly needs as it scraps for points. Tall, quick, strong and a vital cog in the Wolves side that escaped relegation last season, he would be an asset and another option.

Having signed him for around £1 million last January on a deal running until 2020, Wolves would clearly prefer a permanent deal.

Marshall has a number of suitors but few who are prepared to offer that, so Sunderland remain very much in the running and a compromise could be struck that sees a loan until the end of the season agreed with a view to a permanent deal in the summer.

One final position to watch is the holding midfield role.

A serious injury to Darron Gibson, a player who was starring in a vital position, hurt the Black Cats and Coleman had no natural replacement.

That forced the club to begin looking for replacements and some short-term cover.

Ethan Ampadu is clearly a player he rates highly having given him his international debut, and he would offer the added benefit of being able to play both in midfield and defence. It seems highly unlikely Chelsea will loan him out, however. He has impressed Antonio Conte and is a genuine contender for a spot in the first team squad. Having already loaned out Kenedy to Newcastle and Clarke-Salter to the Black Cats, they are unlikely to weaken their squad further.

Another realistic option is the Bournemouth midfielder Emerson Hyndman.

Hyndman came through the ranks at Fulham during Kit Symons' time in charge there and he was impressive on loan at Rangers last season. The Black Cats are monitoring his availability and believe he is a player who could add some creativity and composure on the ball.

Sunderland have also been linked with a move for West Brom's talented holding midfielder Sam Field.

They could well yet decide against bolstering this department as they focus on attacking reinforcements.

Since Gibson's injury Jonny Williams has made a quicker recovery than expected, Lee Cattermole has returned to the fold and Ethan Robson has emerged as a genuine first team option.

Of course, Robson remains inexperienced, Williams has struggled with injuries and Cattermole with form, despite his superb showing against Hull. Those are the factors Coleman, Bain and Symons will weigh up in the coming days.

It is a crucial week, with the window and a game against Birmingham City offering the opportunity to really assuage relegation fears.

There are plenty of irons in the fire but of course, the hard part is getting deals over the line.

Sunderland fans will understandably be anxious as the wait for another definitive breakthrough goes on.