Liverpool appear to have the best chance of ending their league title drought since Roy Evans's team fell away in the finishing straight in 1997, but their Carling Cup exit on Wednesday has revived concerns over their strength in depth. While their first XI looks formidable, the back-up players have struggled to match those standards, again falling short in the 4-2 defeat by Tottenham Hotspur at White Hart Lane.

Fernando Torres and Daniel Agger were the only first-choice players in the Liverpool starting line-up on a night when Rafael Benítez's team suffered their second defeat away to Tottenham in 12 days. But whereas the visiting side were unfortunate to lose 2-1 in the Barclays Premier League, they were poor on their return to North London this week.

Agger, who was part of a defence that conceded three times shortly before the break to leave Liverpool 3-0 down at half-time, claimed afterwards that no trophies, Premier League or otherwise, would be going to Anfield if they continued to play in the same manner. “If you see the goals, it was the same problem every time and they speak for themselves,” the Denmark central defender said. “We conceded four bad goals and you cannot expect to do that and still get anything out of a game.

“Right now it's difficult to take any positives at all. That just wasn't good enough. We have to do better than this otherwise we won't achieve anything this season.”

Liverpool will hope that they can get through the season without many injuries to their leading players, but such a scenario might be less devastating for Arsenal. While their failure to win the Premier League over the past four years has been blamed partly on Arsène Wenger's reluctance to address weaknesses in his first XI by acquiring established top-class players, the manager can boast an abundance of riches in reserve.

The Premier League's “big four” rested most of their first-choice players in this week's Carling Cup fourth-round ties, but Arsenal recorded much the best result. Chelsea joined Liverpool in departing the competition, succumbing in a penalty shoot-out at home to Burnley, while Manchester United needed a late penalty by Carlos Tévez at Old Trafford to see off Queens Park Rangers, but Wenger's team steamrollered Wigan Athletic.

Arsenal's achievement was all the more impressive because their line-up featured a majority of what amounted to third-team players, whereas United and Liverpool had two each and Chelsea had none. Wenger also declined to pick any of his first-choice team, in contrast to Benítez, Luiz Felipe Scolari and Sir Alex Ferguson (although it could be argued that the United manager no longer considers Gary Neville to be his main right back, in which case the Scot also overlooked his entire first team).

Steve Bruce, the Wigan manager, described Arsenal's youngsters as “frightening” and admitted that “we got our backsides kicked by a very good team”. The six players who started at the Emirates Stadium but who would probably not make the club's second XI are Gavin Hoyte, Jack Wilshere, Mark Randall, Fran Mérida, Jay Simpson and Carlos Vela, teenagers all. Among them they provided the goals - two by Simpson and one by Vela - and two of the three assists.

Five of this half-dozen also started the 6-0 win over Sheffield United in the previous round. The only possible drawback for Arsenal fans is whether any of these players are ready to make a significant contribution to the present Premier League campaign. The answer to that question, and the depth of their rivals' reserve strength, may help to decide the destination of the title.