Richard Cockerill says it is vital to keep the playing squad as mentally and physically fresh as possible in the run-in to the end of the season.Leicester Tigers have just four league fixtures remaining and have a weekend off at Easter after being knocked out of the European Champions Cup during the pool stages.   Instead, the players aim to report back to training feeling refreshed and ready for the four game run-in against Saracens, London Welsh, Wasps and Northampton Saints.   “We’ve got some tough games coming up, but we are up there in the mix,” said Tigers director of rugby Cockerill after last Saturday’s 25-18 victory over Exeter Chiefs.   “The top four was our target at the start of the season and that is still our target now. But we have to keep going.   “We just need to regroup and freshen ourselves up. With being out of Europe, we brought our internationals straight back into the squad against Exeter because we knew they could have some downtime after that.   “They’ve been away in national camps for a long time and now it is about being mentally fresh. That can be hard at this time of the season.”   The run-in resumes at Allianz Park next Saturday when Tigers face a Saracens team currently in second place in the Aviva Premiership table.   “All of the top five or six have some tricky games in the run-in, we all play each other at some point too and it will go to the last weekend for everybody,” added Cockerill.   “We’ve had our problems over the season but we’re a good side and we’re working hard to stay up there.”