Chelsea were not sharp in their opening Premier League game, but is Club World Cup to blame?

Five short weeks after winning the Club World Cup at MetLife Stadium, Chelsea returned to competitive play at Stamford Bridge on Sunday, banners celebrating their latest championship adorned around their stadium. The Blues, though, swapped an impressive 3-0 win over Paris Saint-Germain last month for a sluggish 0-0 draw against Crystal Palace, the scoreline a perfect reflection of the performance.

External factors likely played a sizable role in Chelsea's underwhelming showing on Sunday, the Club World Cup creating wonky preseason schedules for the European teams that made deep runs. Enzo Maresca's side, for example, played an 11-month season, took three weeks off, and had just 13 days of preseason preparation before facing Palace on Sunday, while the opponent had a much more traditional build-up. Maresca did not feel his side were underprepared as a result, but it was hard to ignore the circumstances.

"I don't think [the team was unprepared] because, until the end, we competed," Maresca said. "We tried to win the game. I think we had some chances at the end with Estevao, with Andrey Santos. So that showed that probably we compete overall quite good. For sure, [Palace] have already played seven, eight games. And for us, last week we played two games, but we tried to share minutes. So the real game for us was today. But for sure, slowly, slowly we're going to be better."

How to watch West Ham vs. Chelsea, odds

• Date: Friday, Aug. 22 | Time: 3 p.m. ET
• Location: London Stadium -- London, England
• TV: USA Network | Stream: Fubo (Start watching, save $20!)
• Odds: West Ham +390; Draw +300; Chelsea -145

Even then, Chelsea have room for improvement as they prepare to face West Ham United on Friday, a trip to the London Stadium offering a perfect opportunity to put Sunday's performance in the past. While Palace were organized defensively and provided real hurdles for the Blues' attackers, the Hammers are unlikely to pose the same challenge. West Ham are coming off a 3-0 loss to newly-promoted Sunderland, which could be the first sign of a troubling season ahead for a team that has not refreshed much this summer and poses a limited attacking threat.

Chelsea were clearly the more dominant attacking team on Sunday, when they outshot Palace 19 to 11 and generated almost a full expected goal more than the Eagles. It was a performance that was more about quantity than quality, though – the Blues took just three shots on goal, unideal no matter the preseason disruptions. It offered a stark reminder that despite the Club World Cup triumph and the UEFA Europa Conference League win before that, Maresca's Chelsea may have plenty of potential but are still a great unknown.

Maresca boasts a bloated squad jam-packed with attackers, but has yet to figure out what his preferred combination is yet. Considering the circumstances – specifically, an ownership group that is unusually eager to sign new players – it is understandable that the manager has not cracked the code just yet. Cole Palmer has earned the right to be a regular starter but the rest of the spots just might be up for grabs.

The journey to figure out Chelsea's first-choice attacking unit has been a constant feature of Maresca's tenure at the club but the Club World Cup run offers important context thanks to the introduction of a batch of new players. Liam Delap, who chose Chelsea despite interest from several clubs around Europe, was a starter at the start of the summer tournament but by the time the trophy was in the Blues' sights, Joao Pedro was in the mix. He joined the team midway through the tournament and notched three goals in three games, including one in the final, and translated that into a start on Sunday against Palace.

Joao Pedro was at the top of a 4-2-3-1 that included Palmer, as well as Pedro Neto and Jamie Gittens on the wings, but the returns were not spectacular. Joao Pedro took just two shots in 73 minutes, a throwback to his average returns during his two years with Brighton and Hove Albion. The less-than-exciting outing for Chelsea, though, perhaps opens the door for Delap to earn a starting role while 18-year-old Estevao Willian may play a sizable role himself this season after making a 36-minute cameo on Sunday.

Friday's match at West Ham, then, feels like the unofficial start of auditions to be one of Chelsea's first-choice attackers, all of whom will be tasked with helping the Blues live up to the hype they created last season.