Arsenal manager Mikel Arteta fears title rivals Liverpool have assembled the strongest squad in the Premier League following the acquisition of Alexander Isak.Liverpool broke their transfer record twice this summer to sign Florian Wirtz from Bayer Leverkusen, in a deal which could rise to £116 million, before spending £125 million on Isak on deadline day.In all, the champions spent over £400 million on new signings – some £200 million more than Arsenal, who themselves recruited eight new players this summer.Liverpool have secured an ominous nine points from nine available and signed off for the international break with a 1-0 win over Arsenal at Anfield.And when asked how the arrival of Isak at Anfield could shape the title race, Arteta, whose side finished 10 points behind Arne Slot‘s side last season, said: “They are the strongest for sure.“They have recruited the two most decisive players that were in Europe in the market (Isak and Wirtz), and they did really well to do that.“They were very, very strong, and we need to look at ourselves and what we have to do in terms of our abilities to be better than them.”Pressed as to how hard it could be for Arsenal to stop Liverpool this season, Arteta replied: “It is not about Liverpool, but the league in general and how difficult it will be with the level that it is to be so consistent and win the amount of matches you need to earn the right to win the title. “That is going to be a really long run for all of us.”Arsenal take on Nottingham Forest at the Emirates Stadium on Saturday lunchtime, and they will again be without Bukayo Saka following a hamstring injury he sustained in the 5-0 win over Leeds on August 23.However, Arteta allayed fears that key defender William Saliba could be absent for a prolonged period after he confirmed the France international – who played just a handful of minutes in the defeat at Liverpool – trained on Friday and is in contention to face Forest.