Looks like we have an enthusiastic cricketer from the beautiful city of Prague. That's so refreshing to know!
has already made some superbly well-informed comments on your specific situation. I'd second SOC's suggestion that stretching your muscles more than specific weight/strength training is a good idea.
Living in Europe myself, I can appreciate that the layoff during the off-season can be rather long. If you can find some indoor net facility for practice during winters, that'd be great. If not, I'd suggest playing some other sport through winter to keep you fit. From a personal perspective, badminton and indoor volleyball work very well. Badminton, in particular, because it doesn't consume a lot of time, stretches and strengthens your core muscles brilliantly apart from giving you a very fun workout. All depends on your time and the availability of facilities, of course.
That in addition to regular jogging and sprinting should take care of your fitness needs in winter.