Speakers near back wall is not good either. Simply putting big absorbing panels behnd them will null the reflections that would arise if the speakers were further from the wall. But as a needs must, compromise solution that is the best you can do
Position the screen between the speakers, not behind. This will affect the sound least as there is little output from the sides of the speakers. But covered with cloth absorbents or not, the large flat area of the screen will block sound transmission around the room, with unpredictable results.
Incidentally, the sub-optimal speaker placement suggests you may have a smallish room. If this is the case your screen may be too large. The width of the speaker should not subtend an angle of more than 35º at your head. This is the maximum width of the high-resolving central area of our retinas.