One cautious game and one open game, both shaped by who is missing.
Cagliari against Bologna: both teams are short of forwards. Bologna lose two attackers and a centre-back, Cagliari lose their forwards too. Cagliari concede about a goal a game and keep clean sheets regularly, Bologna score little away, and the last meeting was goalless with no meeting in the sample producing a high total. I expect a low-event game, so I'm on the low total side.
Mainz against Bremen: Bremen are down three defenders and still scored twice in each of their last two games with the same absentees. Mainz take a lot of shots at home and Bremen concede plenty of chances. A Mainz push should open Bremen up, but Bremen can still hit from transitions and set pieces. That's why I'm siding with goals at both ends here.