Liverpool legend Jamie Carragher said that the team's performances in games against AC Milan, Crystal Palace and Bournemouth made him less confident about the Reds' chances of retaining the Premier League title.
Arne Slot's men started the Premier League season with a 4-2 win over Bournemouth, but they required an 88th-minute goal from Federico Chiesa to get over the line.
That game came five days on from another game in which Liverpool conceded two goals: the Community Shield, against Palace, which the Reds lost on penalties.
Including pre-season games, Liverpool has kept just one clean sheet in its last 13 games, and the pre-season tour of China saw the Reds concede four goals in a defeat by AC Milan.
It is defeats like the one against Milan that has prompted Carragher to ask questions about the Reds just one game into the new Premier League season.
"I am less confident," Carragher said about Liverpool's title chances on Sky Sports. "It isn't just this weekend, it's the Community Shield and the pre-season game against AC Milan. I saw some things in the Community Shield, which is a semi-friendly, that I didn't think I would see on Friday against Bournemouth. That worried me a bit.
"I said a few days ago that Arsenal would be Liverpool's biggest challengers but I was realy impressed with Manchester City, who I actually think might be the closest challenger."
Meanwhile, Gary Neville back Arsenal to finally get over the line this season but said he had a hard time predicting who will win the league out of Arsenal, Liverpool and Manchester City.
Neville told Sky Sports: "I couldn't separate them so I just went for the team I've gone for the last three years. They're reliable and solid, and they're consistent, which I think is important.
"They're consistently getting high points totals and finishing second to great teams, so I think that they've improved themselves.
"Gyokeres, I wasn't negative about him yesterday... I saw some things in that game. I thought De Ligt did well against him but there were moments where he was a bit uncomfortably with him but I think he'll do well for Arsenal.
"Zubimendi didn't have his best game but I think he'll slot in well, Declan Rice couldn't be any worse yesterday. I think Arsenal have got the right material. They're just going to have to sort that forward bit of the pitch out and I think Gyokeres will.
"I couldn't separate Arsenal, Manchester City or Liverpool. I think they're absolutely all in with an equal chance of winning it. Arsenal have been consistent over the last three years, they've been second. I do feel they'll get there at some point.
"Liverpool, the two full-backs have got to settle in. They look a little bit open. They are going to be exhilarating to watch. They're going to score a lot of goals. City have an unbelievable spine."