Contracts for employment, such as a coach’s contract, are not specifically enforceable (in other words, you can’t enforce a contract of employment to compel someone to keep working for you). That is because it would be akin to slavery.
I would therefore expect that Ivan’s contract would allow him to leave Tigers on giving notice (whatever that notice might be under the contract). However, even then, he could simply walk away from it.
There could be a restraint clause in the contract that restricts Ivan from working for other clubs for a certain period, but that is also very unlikely to be enforceable because the market for coaches is so small it would likely leave him without work at all.