Bayer Leverkusen striker Stefan Kiessling is convinced his team will be a force in Bundesliga this coming season, despite a number of departures.

The likes of Gonzalo Castro, Josip Drmic, Stefan Reinartz and Simon Rolfes have left the club since the end of 2014-15, raising doubts over Leverkusen's hopes for another top-four finish.

But Germany international Kiessling has warned against underestimating Leverkusen, who have recruited Admir Mehmedi, Jonathan Tah and Andre Ramalho, while Kyriakos Papadopoulos signed a permanent deal after spending last season on loan at the BayArena from Schalke.

"It's definitely a big loss, not only sporting but also on a human level because they are three top characters," Kiessling told Bundesliga.com, when asked about Castro, Reinartz and Rolfes.

"But football's like this, people come and people go. What's more important is that those brought in fit in.

"We've got many very young players who have an incredible amount of potential. If they succeed in proving their potential, then I'm convinced we're going to have a competitive squad."

While Kiessling is bullish about Leverkusen's chances this term, the 31-year-old knows reigning champions Bayern Munich remain the team to beat.

"There are going to be plenty of sides jostling for the sought-after Champions League slots," he added.

"I think Borussia Monchengladbach will have another good season, Schalke have strengthened and [Borussia] Dortmund are going to come back too. Then there's Wolfsburg, of course, and we're there still too.

"But let's not beat about the bush – a heck of a lot has got to go wrong for Bayern, and conversely so much has got to go right for their rivals, for the title not to end up in Munich.

"We'll definitely give it our best shot, and I'm convinced we'll be up there among the leading sides again."