My back-up leftback is unhappy because he isn't getting any games. He's old and rubbish and his contract is up at the end of the season which is only a couple of months away. He's only played a couple of times all season, my main choice has been fit and healthy and putting in great performances week in week out.
What are the chance that if I release him on a free now, my main leftback will get injured within the next couple of games?
Look at your other defenders and see if any of them are left footed or can play on the left then give them a game or last 15/30 mins at LB each game to build them up to that position. Then he can go and you have emergency cover. I like players who can play D R/L/C in my squad to cover any problems.