I agree that there is nothing wrong with being defensive. But for once, I have to disagree with Prince EWS. The Test match is not played in a vacuum. It's part of a series, you either lose, draw or win. If you lose this match, you've still lost the series and it doesn't matter. If you win, you have a chance to draw the series, which is a hundred times better.
There is a time to draw matches, and there is nothing wrong with it. But you can't just concede the series without trying. South Africa had to go for a win in Australia a couple years back and ended up losing, but that's exactly what they should have done.
A lost series is a lost series. I can see going for a draw when you're 3-0 down in a four match series with one to play, because you've already lost the series and you don't want to get swept. But if you have a chance to win, and you decide strategically not to take it, it's very poor play for mine. I can also see if the series is tied and you're happy with a draw and don't push for the win. But I don't see how many professional cricketer can be happy with a lost series. Unless you are Bangladesh and a draw is a big achievement for you, it's very poor play if they don't even try.
They need to score between four and five runs an over on a final day of a Test match to win, and that's almost impossible to sustain (considering how rarely that's happened), but you've nothing to lose in the context of the series and they should go down blazing.
They should see off the first five-ten overs tomorrow, see how the pitch is playing and go from there. Even if the pitch is a nightmare, they need to buckle down and go for the win. Remember, it's their ONLY hope of improving the outcome of the series.