Richard Cockerill says his Leicester Tigers squad will get stronger over the opening rounds of the new Aviva Premiership season as he welcomes players back from injury and integrates the new arrivals.Speaking at the Aviva Premiership launch event at the Twickenham Stoop, the Tigers director of rugby confirmed Owen Williams, Jordan Crane and Dom Barrow are making good progress in their recovery from injury.   And with back-rower Brendon O’Connor and scrum-half Jonno Kitto to come into the squad at the end of their ITM Cup commitments in New Zealand, as well as his players at the Rugby World Cup, Cockerill says the squad will get stronger over the coming weeks.   “Owen is doing well and Jordan will come back in,” he said. “Dom Barrow is coming back from injury, the new boys have settled in well and we have O’Connor and Kitto still to come, so the squad will get stronger.”   Cockerill said he hopes Manu Tuilagi will be available in the new year as he returns from a groin injury, and that discussions were ongoing over a new contract for the Tigers centre.   “He wants to stay and we want to keep him, those two ingredients are essential,” said Cockerill.   “We want him here for the long term. He is still 23, there’s a lot of rugby ahead of him. He can play for the next 10 years. We are determined to look after him, as we have done with his injury.   “We are hoping by early new year that he will be playing again for us and that he gets back into the England squad.”   Cockerill, however, reported a knee injury for prop Michele Rizzo, sustained on Rugby World Cup duty with Italy, is likely to see him sidelined for up to eight months.   “We’re disappointed that Michele has damaged his ACL and will probably miss the majority of the season,” he said. “That’s disappointing for him and for us.”