The Toronto Maple Leafs and general manager Kyle Dubas have a tough summer ahead of them and it just got tougher. 

Aside from the whole Mitch Marner situation, the Leafs have big problems on their blueline. 

Jake Gardiner is likely gone through free agency and Travis Dermott just had shoulder surgery so he won't be around for the first part of the season. 

The team doesn't have much cap space to find a solution and now one of their top four defenseman has just requested a trade. 

According to NHL Insider Bob McKenzie, defenseman Nikita Zaitsev has requested a trade out of Toronto. 

Zaitsev has been playing big minutes under Mike Babcock and became Jake Muzzin's partner down the stretch. 

What makes the situation even worse is the Leafs have no cap space to take on another contract and Zaitsev is owed $4.5million a season for the next five years, the Leafs probably won't get any significant return. 

McKenzie also adds that the Leafs don't believe top defensive prospects Timothy Liljegren and Rasmus Sandin are ready for the NHL yet. 

Source: Bob McKenzie