I had a similar problem, I was only getting 20 mins sleep per nap out of him. I ended up starting to wrap him, then he started sleeping for 2 hours!! He was just over 3 months when this started to happen for us. He was sleeping great at night time, so I left that as it was, his morning sleep was also fine, so the wrapping was mainly done in the afternoons.
It was definitely worth trying for us as it worked!!!!
Good luck with it, its definitely worth it