By Karen Pickering
Four-time British Olympian and BBC 5 live summariser on the teenager who beat Olympic champion Rebecca Adlington and world silver medallist Jo Jackson in Swansea
Jazmin Carlin has been around for a couple of years now, and she was swimming very well and very fast last year.
In any other generation, she would have been the star of British freestyle swimming
When Jo Jackson beat Rebecca Adlington to break the 400m world record at the British Championships last year, Jazmin wasn't far away, two places back.
In any other generation, she would have been the star of British freestyle swimming but she is competing against two of the best swimmers in the world.
But I was pretty impressed with her when she won bronze in the 4x200m relay team alongside Becky Adlington, Jo Jackson and Caitlin McClatchey at the World Championships in Rome last year.
She was the least experienced of the four but she was really impressive.
Jaz has stepped up a gear this year on the individual side and she is a tough little cookie.
I think she is going to be in the mix - along with Caitlin as well - for those individual spots at the European Championships in August this year.
I wouldn't be surprised if Jaz doesn't sneak in there because she has all three events - the 200, 400 and 800 - to aim at.
Becky has dominated the 800 and Jo has started doing it and is improving, but Jaz has a chance in that and you can't write her off in the 400 either because she is so fast.
This is a weird time of year for swimmers in training and each of them reacts differently when they are racing.
Some of them like Jaz, who is smaller than Jo and Becky, don't need too much rest.
But Jaz has certainly stepped it up and given the other two girls something to think about at the trials next month.
Karen Pickering was talking to Bryn Palmer