And Leven will join a team in form as Pezinok are currently 17-5 and sit joint top of the Extraliga.
"I wanted to stay at a higher standard so that when I come into camp in the summer I know I have been playing a good level which will make me more competitive," said Leven.
"The deal is until the end of the season and then after that we will see.
"I spoke with Chris (Finch) about my situation and he thought it was the best option. I called him to get some advice and he said it would be a good move.
"They love their basketball out there and I know they have a very rich basketball culture. I'm looking forward to getting out there as soon as possible to play with them."
Meanwhile after starting the season in the ACB, Mensah-Bonsu has returned to the D-League where he will wear the no.44 jersey for the Toros.
Last week fellow Brit Andy Betts signed for Greece's Aris Thesaloniki while Flinder Boyd joined the BBL's Leicester Riders earlier this month.
Meanwhile the City of Sheffield Hatters collected the Women's National Cup for a record breaking 12th time after a 76-59 victory against UWIC Archers.
Stephanie Gandy picked up the Most Valuable Player award after finishing the game with 23 points, 13 rebounds, three assists, three steals and a block to lead Vanessa Ellis' team to victory at the Amaechi Centre. Sarah Naylor finished with 18 points, including three treys, while Taylor added 16. For the Archers Meagan Hoffman led the way with 19 points and eight rebounds with fellow Great Britain international Collins finishing on 17 points and seven boards.
