XPath "how many elements in node?" with Microsoft EXCEL

I'm trying to use Microsoft Excel's FILTERXML function to grab data from an XML form.

I'm not quite sure why I'm unable to get a number response when I use certain XPath arguments.

Here's my XML:

<result>
<status>1</status>
<num_results>1</num_results>
<total_results>500</total_results>
<results_remaining>499</results_remaining>
<matches>
    <match>
        <radiant_team_id>0</radiant_team_id>
        <dire_team_id>0</dire_team_id>
        <players>
            <player>
                <account_id>141684701</account_id>
                <player_slot>0</player_slot>
                <hero_id>0</hero_id>
            </player>
            <player>
                <account_id>4294967295</account_id>
                <player_slot>1</player_slot>
                <hero_id>0</hero_id>
            </player>
            <player>
                <account_id>4294967295</account_id>
                <player_slot>2</player_slot>
                <hero_id>0</hero_id>
            </player>
        </players>
      </match>
   </matches>
</result>

I'm trying to use this XPath argument to count how many players pop up in a dynamic API that refreshes an XML form every so ofter. The player count varies from 0-10.

/result/matches/match/players[count(player)]

I get a #!VALUE error. Here's the MS Excel function argument I use:

=FILTERXML($A$2,"/result/matches/match/players/player[count(player)]")

Both arguments fail. Is there a way I can report how many player elements exist in the XML form by reporting to another cell in MS Excel?