Maurizio Sarri is expecting a tough test against a Dynamo Kiev side he believes are physically ahead of his Napoli outfit.

The two teams go head-to-head in the Champions League on Tuesday in their opening Group B game at Kiev's Olympic Stadium.

And Sarri has predicted that Napoli will have their work cut out in what he calls a potentially "problematic" first fixture, with Dynamo already seven games into their season.

"Right now, they physically may have something more than us," he told a news conference. "We are not from a country where the season can start earlier like they do.

"It's problematic, we know, and we have to overcome them on the pitch."

Sarri knows how important it is that Napoli get off to a strong start, given their status in a tight group which also features Benfica and Besiktas.

"This group is perhaps the only one in which all four can go through," he said.

"It will be a complicated game as it has been between Italian teams and [fellow Ukrainians] Shakhtar Donetsk."