Loan players can be found in the 'Loan Market' which is regularly refreshed (every 6 hours), showing a new group of 6 players each time. 

The 'Loan Market' is the same for all club owners (everyone sees the same group of players at the same time).

Loan players are purchased via spending Transfer Coins (which you get from rejecting Agent offers) and the cost of each loan will differ depending on the player's rating. For example, a 79 rated Bronze player would cost 1,200 Transfer Coins on loan, whereas an 84 rated Gold player would cost 6,000 Transfer Coins.

Loan players are shown on your squad screen with a blue outline. 

Loan players do not cost anything towards your salary cap but will only stay in your squad for only one match (note: they do not leave your club if you don’t line them up in your starting 11 or if they do not play in the real world - you will keep them until they play for you). Loans cannot be extended.