What Arsenal needed before the biggest game in their recent history was momentum.

What they didn't need was a full-strength side going down to a first-ever home defeat by Bournemouth.

Unfortunately for Mikel Arteta that is what happened as the Gunners' preparations for Wednesday's pivotal Champions League semi-final second leg at Paris St-Germain were dealt a blow by Saturday's 2-1 loss to the Cherries.

Arsenal's aspirations for the remainder of this campaign rest entirely on success in Europe, and they head to the French capital needing to overturn a 1-0 loss from the first leg.

That task looks even harder now, after Bournemouth battled back from Declan Rice's opener with two goals in the second half, but Arteta believes such a loss could ultimately work in their favour.

"It didn't create the right momentum," he said. "It created a lot of anger, frustration, rage, disappointment.

"Let's use all of that on Wednesday. That's what we have to do."

What do Arsenal need to do to beat PSG?

For a start, the Gunners need to be better at defending set-pieces.

While they were far from at their best against Bournemouth they were in control of the game, as the visitors did not manage a shot on target for the first hour.

But their first such attempt resulted in an equaliser as Dean Huijsen headed in from Antoine Semenyo's long throw.

A set-piece was again Arsenal's undoing for the winner as a corner was flicked on to the far post for Evanilson to bundle in.

Of the goals Arsenal have conceded this season 38.7% have come from set-piece situations - the most in the English top flight.

Arsenal have to score on Wednesday and then somehow keep out a PSG side that has scored a league-high 42 goals in 16 Ligue 1 games at home so far this season.

In their past five Premier League games Arsenal have taken the lead, but in four of those games they failed to hold on to that advantage.

In total they have dropped 21 points from winning positions in the Premier League this season, their joint-most in a single campaign (also 21 in 2019-20).

Read Also: PSG Beat Arsenal to take Advantage in Champions League Semi-Final

The other concern to arise from Saturday's defeat was that after Bournemouth took the lead in the 75th minute, the Gunners did not manage a single attempt on or off target.

"At the minute, looking at that you just cannot see it [Arsenal beating PSG]," former West Ham goalkeeper Rob Green said on BBC Radio 5 live.

"You take Declan Rice out of the equation of this team and you've got a group of players bereft of confidence and ideas on how to score goals and have an incisive edge.

"There's work to do and so little time to do it."

'A major wobble' at the wrong time for Arsenal?

For the vast majority of the season Arsenal were Liverpool's main challengers for the Premier League title, but their disappointing run of form recently means they are clinging on to second place.

They are three points ahead of Manchester City in third, but if Newcastle beat Brighton on Sunday that gap will be down to two.

Should Chelsea, who are fifth, win at home to Liverpool and sixth-placed Nottingham Forest triumph at Crystal Palace on Monday then they will be four points behind.

With three games to go that would mean a finish in the top five could be under threat for the Gunners.

"Are the wheels off at Arsenal?" ex-Premier League striker Chris Sutton said on BBC Radio 5 live.

"They are having a major wobble, aren't they?"

It may not be quite as dramatic as that, but Arteta knows the Gunners need to be much-improved from their recent performances to avoid their season fizzling out even more than it is already threatening to do so.

"We have a lot to do, yes, because mathematically we are not qualified [for the Champions League]," he said.

"We haven't had the right to finish second yet, so we still have a lot to do."