It looks like Lazio did not prioritise the Europa League this week. Only four of their starters against Rennes have started more than half their six Seri A games this season, three have yet to start a league game and one, Quissanga has started only once.
Lazio are a point behind rivals Roma in the league and two points off a Champions League spot.
They visit Glasgow in three weeks then face Fiorentina in Florence, who currently have two points less than them, three days later. The game at Celtic Park might be too heavy a load for Lazio to risk the full first team.
The return leg comes between a visit to Milan, currently 16th (!), and a home game against Lecce, who are one place below Milan.