It occurred to me to handle it in the script rather than the html. Working code now is:
<a href="{@current_team.permalink}">{@current_team} {@current_team.age_bracket}</a>
<select id="player_sel_id" name="player" class="players-list">
[each current_team]
[each players]
<option name="{@post_slug}" value="{@permalink,esc_url}" />{@post_title}</option>
[/each]
[/each]
</select>
<script>
document.getElementById("player_sel_id").addEventListener("change", function (event) {
location.href = event.target.value;
});
window.addEventListener('load', function () {
document.getElementById("player_sel_id").value=window.location.protocol +
"//" +
window.location.host +
window.location.pathname;
});
</script>