The north London side host the Greeks tomorrow, having won just two points from their opening two European group games this season.
But both manager and player are targeting a positive result, although they will have to manage without Nabil Bentaleb.
"Asteras is a very good, young team. They won their game against Partizan and drew against Besiktas. They are a good team, very focused," Pochettino told Spurs TV.
"They have a very good philosophy on the pitch and have a lot of Argentine players. They have a very good side. It will be a very important game."
On Bentaleb's injury, Pochettino said: "Yes, Nabil is injured but we hope he can get fit as soon as possible."
Meanwhile, Mason told Spurs TV: "We need a win. We're back at the Lane so hopefully we can pick up the three points and get out of the group.
"We're confident of getting out of the group. We're taking it serious, I think our team selection shows that. I think a draw wasn't a result against Besiktas, who are a good side, and hopefully we can get the three points on Thursday."
Tottenham host Asteras at White Hart Lane at 8.05 pm on Thursday night.