Napoli coach Maurizio Sarri has criticised Serie A organisers for having to play SPAL in domestic competition just three days after hosting RB Leipzig in the Europa League on Thursday, labelling the scheduling as "madness".

Sarri's side are top of the league in Italy, sitting one point above defending champions Juventus after enjoying a stunning season so far.

They return to European competition on Thursday in the Europa League, having been eliminated from the Champions League in the first half of the season.

Sarri made no secret of the fact Napoli will be prioritising their Serie A title challenge over the Europa League, particularly given what he believes to be unfavourable scheduling.

"It is a manifestation on the edge of madness, albeit with the caveat of European football," Sarri told reporters at his pre-match news conference.

"We play on Thursday evening, then we are back on the pitch 60 hours later. The league aren't helping us.

"With respect to stress, it's on the verge of madness, but it is the secondary European competition and it always has charm.

"It may bring us stress in the long term, but for now we are focused on the match.

"We have to play it. We have 18 players, with the three goalkeepers. There are numerical problems, but we will try to play a serious, competitive match without impacting the league [form]."

Sarri also spoke glowingly about Leipzig, calling them a "brilliant" side that "excites" him and he is surprised they were unable to stay in the Champions League.

"We will be facing a team that excites me when I watch them," Sarri said. "They are a fun team, good to watch, with speed and technique.

"Their team is brilliant. They have all the pace in the world and their wingers have quality.

"I was surprised they were knocked out of the Champions League as they had the quality to have their say. They are a really strong team."