They're sitting at the summit with the Premiers' Plate in their sights but Western Sydney coach Tony Popovic has warned the A-League newcomers will be an even bigger force in their second season.Starting this season as an unknown entity, the Wanderers have become the new benchmark after knocking long-time leaders Central Coast off the top of the ladder with a record-equalling eighth consecutive win at the weekend.But Popovic is predicting even bigger and better things next season.With the club hurriedly cobbled together only three months before their A-League debut in October, the Wanderers didn't have the luxury of an entire pre-season as a group - something Popovic says will set them up even better next time around."There's still a lot more improvement," Popovic said on Tuesday."We weren't at our best against Central Coast even though we won."Once this group has been together a little bit longer and had a full pre-season together our football should improve even more next year."With only four games to go, the Mariners sit just two points adrift of top spot.After hosting bottom-placed Wellington on Sunday, the Wanderers then face Melbourne Heart, Sydney FC and Newcastle in the final rounds.The Mariners, meanwhile, take on Sydney FC this week, followed by Brisbane - after a midweek trip to Japan for an Asian Champions League game - then Adelaide and Melbourne Heart.Popovic said his team believed they could stay on top."Of course we do," he said."But we haven't compared what's easier or harder for us or the Mariners, we're just focused on our games."We know that if we're not playing our best, things can change very quickly."We're not expecting any favours from any other teams. We can only control what we do and get the results to stay there."Popovic is anticipating a rejuvenated Phoenix at Parramatta Stadium on Sunday after they broke their four-game winless run with a 1-0 win over Heart last week under new coach Chris Greenacre.He says the last-placed club may pose a bigger threat than many expected."We're not playing the league leaders this week but we're playing a team who have changed their management and have had a fantastic result against Melbourne Heart," said Popovic."They may be coming in with nothing to lose so it will be a dangerous game and a tough game."