Change Profile Image Shape

On the Team Rosters plugin,

Is there any way you can change the player bio profile image from square to any shape you want without the image getting stretched? i.e. I have an image which is rectangular in size and I have set the right image dimensions on the single player css file to 300px wide and 135px high. The image size works but the image is disorted/stretched. Is there a solution to this?

Cheers

https://ww.wp.xz.cn/plugins/team-rosters/