The experienced ice hockey centre was cross-checked near the boards by a Nottingham Panthers player.
And he received treatment for a painful shoulder injury.
It wasn’t the start the bustling Slovakian-born player-coach wanted, particularly as he had shocked Panthers with a rasping shot which clipped the right-hand post after 25 seconds. But the 35-year-old will now have intensive treatment to get him ready for the Capitals’ weekend double-header at Belfast Giants on Saturday and at home to Nottingham Panthers on Sunday (6pm).
Bratislava-born Hartmann, who became a professional player in 1999, has spent most of his career with Skalica HK 36.
Last year, however, he played 44 games for German side Lausitzer Foxes, scoring 14 goals and setting up 18 others.
Hopefully, Hartmann will be on the ice, not supervising from the bench as he did when Panthers won 5-1 last Sunday.
He reflected: “I think we played a pretty good game. We had six imported players and they had 11.
“Our guys played hard. We made a couple of mistakes and they (Nottingham) scored goals, but that was our first game.
“Nottingham have played several league and cup games before coming here.”