I suggest you re-lace the mitt. That may sound easy but it can be a real chore especially with a catchers mitt. The laces follow a very indirect route from point "A" to point "B". Re-lace one lace at a time being careful to follow the path of the original lace. The new laces will actually add a certain degree of "newness" to the old mitt. I will also suggest he ALWAYS keep a ball in the mitt when not being used. This maintains the shape of the mitt. The brand new mitt should have a ball placed in the pocket (some use two balls) and be wrapped with a "saran wrap" type of material to help initially form the mitt's pocket. I'm not a big fan of most glove oils because too much oil softens the leather to a point the mitt can become too floppy too quickly. Cleaning the mitt is very important because dirt is an abrasive and creates premature wear. With the constant pounding of fast balls, the catchers mitt has a definite "cycle" in its life span and should be classified as 1. "too new", 2. "game mitt" and 3. "back-up mitt". When the mitt is new they are too stiff for game play and should be used only in practice or bullpens. A properly broken in mitt is the game mitt. Don't overuse this glove for bullpens. When they become too floppy, worn or stretched they should be used ONLY as a back-up to the game mitt.
Fungo
PS. This can be expensive if the parents have to buy the mitts. My son used two mitts in HS and then in college went to three (college provided) and in the pros was under contract with All-Star that provide all his mitts, gloves, and catching equipment.