In fact, re-signing this player is almost identical to acquire an useful 3* free agent player in next season. If this player is still important in your squad rotation, I suggest you keeping him until a replacement player is found.

When I was at your level, I found that the transfer market has been becoming more and more difficult. If your transfer market is similar and you are unlucky, you may need several days to find a suitable replacement player. At that time, you may miss him and his versatility.

If you do not plan to have add more player to your 19 player roster, I believe you have sufficient cash that you don't need to sell players before buying new ones.