Theo Walcott has backed Arsenal to retain their Premier League crown, but only if they don’t fall apart away from home.The Gunners have won four of their opening five league fixtures, with the only defeat coming away against Brighton.Arsenal only lost three times away from home in the league last seasonGettyIt was a contest the Seagulls dominated, with Arsenal’s frustration perhaps best summed up when Declan Rice kicked out at Malick Yalcouye.The result gave credence to Walcott’s belief that the Gunners, who he described as ‘exceptional’, remain ‘a little vulnerable away from home’.Theo Walcott explains why Arsenal are ‘vulnerable’ away from homePart of Walcott’s reasoning is the drop-off in performance from summer signing Christos Tzolis, who was booked and got taken off at half time in his first away game as a Gunner against Aston Villa.“I like Tzolis, but from what I’ve seen away from home, I haven’t been as impressed,” Walcott said on talkSPORT Drive.“It’s difficult to really shine away from home. You can have those players that are great at home or great at training, but can’t [do it] away when it really matters.”Walcott likened Tzolis’ dip in performances away from home to ex-Gunners star Mesut Ozil whenever Arsenal visited the notoriously vociferous Selhurst Park.“Don’t play him, play someone else, play someone who is going to work for the team or do something different,” Walcott added.Despite his concerns over Arsenal’s vulnerability in away games, even though they’ve picked up six points from a possible nine on their travels this term, Walcott remains adamant the Premier League title will remain in north London.“I think they are exceptional and I do feel they’ve got everything to retain it,” Walcott said.“But it’s not going to be easy, because they’ll want to win the Champions League.”Walcott made nearly 400 appearances for the GunnerstalkSPORTWhat is Arsenal’s record of set pieces this season?Another element of Arsenal’s game Walcott is slightly concerned about is their set pieces.The Gunners used them to great effect last term, netting a league-leading 23 goals from set pieces.However, this season has been a different story as they are yet to get off the mark.And the longer their drought continues, Walcott fears it could lead to some worrying dressing room conversations.Theo Walcott voices fears of Arsenal’s set pieces“I know it’s really early, but it looks like a stressful environment already,” Walcott said.“You look at the set piece side of things, it hasn’t really happened yet. We scored a lot of set pieces at this stage last season, that hasn’t happened yet.Set piece coach Nicolas Jover has become a regular fixture on the touchline when Arsenal have a chance with a dead ballGetty“So take that away and the players will be thinking, ‘Are we doing this right?’“You don’t want the players to be having those conversations, but deep down, they will be, because it hasn’t quite gone to plan.”The Gunners will have to wait until October 18, when they take on Nottingham Forest, to remind the competition about their credentials away from home.