BATE welcome the Gunners to the Borisov Arena for the opening leg of their round of 32 clash after securing their 13th successive Belarusian Premier League title in 2018.
Their final game of the year was a victory over PAOK which ensured just a third appearance in the Europa League knockout stages in the history of the club.
As they enter pre-season to prepare for their title defence, Hleb – who made 130 appearances for Arsenal between 2005 and 2008 – conceded the game has come at a bad time.
"Arsenal are at the peak of readiness – for them this is a huge plus," Hleb told Pressball, a leading sports newspaper in Belarus.
"It will be hard for us, and very much so. But we will try to squeeze the maximum out of the physical form that we have gained.
"The usual preparation is under way. We held a training camp in Turkey and got into shape, as far as possible at the current stage.
"It is clear that we did not achieve ideal conditions in such a short time. But we will try to look decent at home.
"We are not yet ready (to play at) 100 per cent, but the coaching staff decided not to force anything – realising that the guys had to rest after a hard season. And now we are working – in general, everything is according to plan."
Although they secured another league title, BATE have seen plenty of upheaval during the winter, with seven players moving on from the club.
Hleb believes those players, including Belarus internationals Denis Polyakov and Maksim Volodko, will be missed – especially as the team looks to continue where they left off.
"Everyone will be missed," he added. "Each loss is not easy. But such is life: it is clear that now the leadership is thinking about how to replace the departed guys – and get stronger.
"They (new signings) need time to adapt to the rhythm and pattern of the team's game, to feel each other and all new partners. I hope they will have a good season and help the club."