Opponents Yorkshire will be without England players Joe Root and Jonny Bairstow while overseas batsman Travis Head has been called up by Australia.
Fellow Aussie Tait still expects Yorkshire to be dangerous at the SSE Swalec Stadium on Thursday.
"They're a good side so they're going to come here thinking we've got a pretty good side as well," he said.
"Our chances are pretty good. It's going to be a good clash - a very important match for Wales."
The game against Yorkshire is Glamorgan's first home quarter final for 12 years, with treble-chasing Yorkshire starting as favourites.
"I see Travis Head has gone home so that's one bloke we don't have to worry about for Yorkshire," added Tait.
"But they still have David Willey, Liam Plunkett and Tim Bresnan - they're pretty experienced.
"Adil Rashid is absolutely their danger man with the ball.
"There's some really experienced players there who have played international cricket - there's not one stand out."
"From our point of view we just want to make that finals day and whoever stands in our way we're just going to try to knock them off.
"Yorkshire are first up for us and if we can do them on Thursday we head off on the 20 August and have a shot at it."
Both semi-finals and the final will be played at Edgbaston on Saturday, 20 August.
Fast bowler Shaun Tait says Glamorgan have a good chance of progressing to the T20 Blast finals day.