FILE - In this Jan. 5, 2018 file photo, United States forward Brady Tkachuk (7) celebrates a goal during the second period in the bronze medal game of the world junior hockey championships against the Czech Republic in Buffalo, N.Y.  Former NHL star Keith Tkachuk already has one son, Matthew, following in his footsteps. Soon, there could be a second. Brady Tkachuk, 18, is considered the top U.S-born draft prospect after his freshman season at Boston University.(AP Photo/Jeffrey T. Barnes)