Saints currently lie third and have games in hand as they prepare to travel to Brisbane Road to face an Orient side still in with a shout of the play-offs.
"We've got Southampton on Saturday, obviously they are looking for automatic promotion and they are probably my bet to go up automatically," said Slade.
"We know that it`s going to be a very tough game because they have threats all over the pitch.
"They are a very talented side and probably shouldn't be in this division, but we are looking forward to the game."
Source: PA
Source: PA