Some Harvard sports teams might struggle to field teams without foreign students. Not long after President Donald Trump’s first attempt to bar Harvard from enrolling international students last month, the school’s men’s soccer team, along with athletic teams all over campus, received a note from the coaching staff.

The university called it “yet another illegal retaliatory step” from an administration that has sought ways to circumnavigate the courts in its push to bar foreign students.

President Donald Trump has escalated his standoff with Harvard University, seeking another path to prevent international students from attending the school after a judge blocked an attempt to revoke Harvard’s ability to enroll international students.