It is possible but it will take a long time.
You can just go to 'Edit Player' and scroll across to the 'Contract' tab. I'm not sure whether the time you'd invest would be worth it though. First round rookies have 4 year contracts with a 5th year team option. Teams then have the opportunity to franchise tag them for a year, so current rookies are likely to be on their current team for at least 6 years if they're good. Are you really going to be worried about people hitting free agency in year 5 of your franchise instead of year 6? The only other thing that it really impacts is the rookie awards in the first season.
I left the rookies alone, but made sure that players who should be hitting free agency in 2020 were on the last year of their deal in the offseason period.