Wikidata:SPARQL, Soccer players number of games

I used this query at https://query.wikidata.org/ --

SELECT ?p ?pLabel (?oc as ?OC) (?sp as ?SP) WHERE {
                      
?p wdt:P106/wdt:P279* wd:Q937857. # Soccer player

SERVICE wikibase:label {bd:serviceParam wikibase:language "en" . }
                     
{ SELECT ?p (count(?oc) AS ?oc) WHERE { ?p wdt:P106 wd:Q937857; p:P106 ?oc. }  GROUP BY ?p HAVING(?oc<3)} # Occupation

{ SELECT ?p (count(?sp) AS ?sp) WHERE { ?p wdt:P106 wd:Q937857; p:P54 ?sp. } GROUP BY ?p HAVING(?sp>5)} # Sport Teams                                                                                                   
}

LIMIT 10

Query link

After having googled for hours to find a way to sum the number of games (P1350) of each player in all teams (P54), I decided to ask for some help.

SELECT ?player ?playerLabel ?totalMatchesPlayed {

SERVICE wikibase:label {bd:serviceParam wikibase:language "en" . }

{
  SELECT ?player (sum(?matchesPlayed) as ?totalMatchesPlayed) WHERE {
    ?player wdt:P106/wdt:P279* wd:Q937857 . 
    ?player   p:P54/pq:P1350 ?matchesPlayed.
  }
  GROUP BY ?player
  LIMIT 100
}

}