Liverpool suffered their second defeat of the season on Saturday evening, when they lost 1-0 at home to Aston Villa after an uncharacteristically flat performance at Anfield. With Daniel Sturridge missing due to an injury sustained playing internationally, the Reds were forced to switch to a 4-2-3-1 system with Lazar Marković, Philippe Coutinho and Adam Lallana supporting Mario Balotelli up front, all making their home debuts. On paper that side should have been enough to overcome the Villains, but they surprisingly fell victim to a lack of creativity and final product in the final third - rarely troubling Brad Guzan in the Villa goal. In fact, an early Gabby Agbonlahor was enough for the visitors to return home with the three points - after Mamadou Sakho's error in judgement allowed the away side to win a corner, and from the subsequent set-piece, the pacey forward was there to stab home. The hosts never recovered from the early blow and an Adam Lallana strike from outside the box was the closest they came in a game where they lacked fluidity and movement, whilst Paul Lambert's men defended resolutely and they paid for it. It was a blow to the morale for Brendan Rodgers' side, and here's five things we learned from the game:

1. Two forwards make the world of difference. 

In the three games prior to the Villa game, Liverpool had enjoyed mixed success with several different formations. The 4-1-2-1-2 diamond formation was certainly the stand-out set-up that saw the Reds put in the same shifts that saw them light up the league last year. Daniel Sturridge and Mario Balotelli may not have scored against Spurs but the system as a whole suited them, with Joe Allen and Jordan Henderson putting in superb displays whilst Raheem Sterling dazzled in the 'no.10' role. Against Villa, with Balotelli's lack of movement being exposed and Phil Coutinho having to drop deep to pick up possession, meaning he could not influence further forward, Liverpool had no creativity or attacking threat and with a lack of tempo - Paul Lambert's side could easily sit back and soak up the pressure. There will have been a number of causes, but the system was certainly one - the 4-2-3-1 didn't work, and the Reds haven't mastered the 4-3-3 either. The diamond seems to be the way to go, but with Sturridge injured - the dilemma is who to pick beside Balotelli. Choosing Rickie Lambert could mean the same potential problems of a lack of movement in the final third, but Fabio Borini is not yet near to the quality required to maintain a starting berth at the club. Not to mention the fact that both made very little impact when they came on in the dying stages against Villa. That leaves a bit of a selection headache for the Ulsterman - does he pair Sterling with Balotelli? Or does he alter the system for there to be a second support striker who operates slightly behind Balotelli. He'll need to think fast, but Rodgers has worked wonders in similar situations before and so there's plenty of hope for Liverpool fans just yet.

2. Liverpool's defence is by no means settled.

Fresh faces but nothing fresh in the way of defensive instability was the story of Saturday evening, as despite a fan's favourite back-line of Alberto Moreno, Mamadou Sakho, Dejan Lovren and Javier Manquillo - the back four were constantly troubled and were significantly less compact than the visiting defence. Sakho was largely at fault for giving away the corner that led to Villa's goal, but in truth all of the defense were guilty of individual errors throughout the full 90 minutes. It will be a concern for Brendan Rodgers, as the big money spending on new players was supposed to help cement a solid defense, but so far that has not been the case. The Reds particularly struggled from set-pieces and corners, with Philippe Senderos finding himself with a number of costless headers. In fact, Lovren was guilty of letting the Switzerland defender loose in the box to win the initial header before Gabby Agbonlahor scored. Lovren, for all of his leadership qualities, has a lot of convincing to do. With the Champions League soon to get underway, where Liverpool will face the likes of Gareth Bale and Cristiano Ronaldo, they need to tighten up ship or face the consequences. 

3. Balotelli's hit-and-miss reputation looks set to stay. 

For all of his glimpses of promise in the Spurs game, the hard work and pressing which shocked critics - who deemed helped Balotelli mature an impossible task - his performance was particularly dull, if not non-existent, against Villa. He struggled to make his mark, albeit he was considerably depraved of chances on goal. The Italian was actually very impressive in his hold-up play, but the lack of support meant he had no options when the time came and so nothing came of any attack. He struggled to impose himself, which was a worrying sign, but he did show signs of a new and improved attitude at his new club. It was clear for everyone to see that Paul Lambert had insisted upon his defenders frustrating the Italian as much as they possibly could and Senderos purposefully fouled him a number of times - miraculously leaving the field without even a card. Alan Hutton too, left his mark on the forward but rather than impetuously react - Balotelli simply left them to it. A remarkable difference to the Mario everyone knew in Italy and at Manchester City. The 24-year-old also kept his cool despite the obvious frustration of having very little ammunition in the arsenal. Previously, he may have sulked and complained about his teammates poor performances but again he kept his head down and tried to do his duty. So, though there were negatives, there were some positives too from Balotelli's game. His time will come. 

4. Sterling is crucial. 

One noticeable absentee, in addition to Sturridge - was teenage whizz-kid Raheem Sterling. The 19-year-old was rested after international duty, and his non-attendance was certainly telling. Despite Lallana, Coutinho and Marković lining up behind Balotelli, Sterling's cutting edge and directness was missed. Liverpool instead opted to hit it long via Steven Gerrard to the full-backs and get it into the area but it never seemed to work for them. Sterling has maintained his impressive form from the closing months of 2013-14 and was the side's best player against both Southampton and Tottenham, and his growing importance was shown with the Reds' struggle without him. He came on after the hour mark and immediately added a bit of buzz, though it would turn out not to be enough, and his impact cannot be understated. His speed, dynamism, movement and the distraction he causes in the final third can trouble any defence and he will be relied on more and more as the season goes on. 

5. The new-look side needs time to gel. 

There were a number of the club's summer signings crammed into the Liverpool side on Saturday, and it was evident throughout the game, as Lallana, Marković, Moreno, Manquillo, Balotelli and Lovren were all far from their best. The ex-Saints skipper made his first performance on Saturday, whilst Marković, Moreno and Balotelli all made their Anfield debuts. Though it was expected that team would have been enough to overcome their opposition, their playing styles were out of sync and as a result the team as a whole were uncharacteristically jarred and lacked flair. All of them showed miniature examples of their talent, but it was never enough to change the game and because they didn't gel together - Sterling and Sturridge were missed massively. The chemistry has time to grow yet, but as the campaign becomes increasingly difficult - consistency is going to have to be found sooner rather than later.