United travel to Brentford with former Bees striker Bryan Mbeumo in the travelling squad.
"They've got a very talented set of players," said Andrews. "They have a very defined way of playing the game that they know very, very well.
"They've added some quality players; one who left this building to join them, who we're very well aware of!
"They will cause us a lot of problems if we don't do things correctly.
"I watched (the 4-3 win in May) back this week, as well as their other games this season, because the personnel makes a big difference, especially at the top end of the pitch.
"They've added Bryan, (Matheus) Cunha and (Benjamin) Šeško this summer, and we've looked at how they might be different compared to how they were when we played them at the end last season.
"The system might be the same, but the personnel is different."