The landscape of this Premier League season has changed, and it will continue to do so until the end of this month’s transfer window.

Arsenal, currently in first, look to hold with what they have and hope for the best. Theo Walcott is out for the rest of the season, but Arsene Wenger is boosted by the returns of Lukas Podolski and Alex Oxlade-Chamberlain. Pivotal figures in Aaron Ramsey and Mikel Arteta are also on their way back; Nicklas Bendtner, regardless of his detractors, is a useful member of the squad. But with Wenger continuously speaking out against the opening of the market midway through the season, he may cost Arsenal the title if he chooses not to act.

There is chopping and changing with what Arsenal need. In December, even after the result at Manchester City, Arsenal looked good value for the title. They had managed to negotiate their way through the Champions League group stages and past the wealth of City and Chelsea to the top of the league table. They’d done that without two vital scoring components in Podolski and Walcott. With those two back, it looked to be a boost for Wenger’s side’s charge on the league title.

But needs change, and not just because of what happens within your own squad.

Chelsea have strengthened. The sale of Juan Mata won’t be felt within Jose Mourinho’s team. What they really needed was to address the centre of midfield, and they’ve done that now with the re-signing of Nemanja Matic from Benfica. We can take the easy route of criticising Chelsea’s transfer policy, but in terms of what they needed at this time, Matic is an excellent buy. Chelsea have just thrown another log onto their own fire, fuelling their push to the summit of the league table.

Manchester United, though not a direct player in the title race, will have a say in the outcome in May. Their capture of Juan Mata, which at time of writing is yet to be made official, will be seen as a phenomenal boost to their hopes of finishing fourth. With Wayne Rooney and Robin van Persie returning in the near future, that game at the Emirates on February 12th has been made that much more difficult with the involvement of Mata.

Chelsea and United are fortunate that the exact players they needed have become available at this point of the season, though many have questioned United’s need for Mata. Arsenal need a striker who is either better than what they have now in terms of out-and-out goal scoring, or a good enough player who will help them over the line and get them to the summer window.

Mirko Vucinic, a good short-term option, looks to be off the table for now. Juventus want a permanent deal but Arsenal are only interested in a loan. Alvaro Morata, Dimitar Berbatov and one or two others around Europe have been touted, but the deal proposed by one party doesn’t suit the other. Arsenal would like to have Morata on loan; Real Madrid are reluctant to let him leave. Even wide players, with Fiorentina’s Juan Cuadrado linked in the recent past, looks to be a difficult area of the market. The Fiorentina winger would be a good addition at Arsenal, but having just lost Giuseppe Rossi to injury, the Serie A side understandably won’t want to lose key players in the market.

Is this an excuse for Arsenal? Yes and no. You can understand the situation the club are in, but at the same time you wonder if the club themselves understand the position they’re in at this stage.

There are players around Europe who don’t hold the same profile as Mario Mandzukic or Luis Suarez who would nevertheless be a fantastic boost to Arsenal’s title ambitions. They may not initially be the first or second choice, but in situations like this, where others are actively strengthening, compromises need to be made.

But it’s not just the addition of an extra player that will help on the pitch, it’s what they will do for the mentality of those already at the club.

United’s players, those down on confidence, will be boosted by Mata’s arrival. You’d struggle to imagine many of them not wanting to raise their game with the Spaniard in the red of Manchester United. Arsenal need the same. At times important players have looked fatigued, in need of a helping hand and a catalyst to help them find that extra 10 per cent. It can’t be dismissed the importance a new arrival can have in a season like this.

To borrow a phrase from Wenger, Sergio Aguero is like a new signing for Manchester City. And if Manuel Pellegrini decides to include Stevan Jovetic for the remainder of the season, the Montenegrin will also have a say in the title race.

Arsenal, as good as they’ve been as a unit, could do with an injection of quality like that. Maybe not a £30 million player, but someone who can help to make a difference.

The league season is changing. It’s even less straightforward than it was before. A month ago it seemed OK for Arsenal to let this month go by without any action. Now, amidst the transfer business of others, a lack of action just might cost Arsenal the title.

Click below to see Arsenal, Fulham and Everton in action this weekend!