Paul Lambert admitted welcoming back Ron Vlaar was a big plus for his side as they get set for the start of the 2014-15 season.
Vlaar linked up with the squad in his native Netherlands to watch the Groningen match.
Despite the defeat, Lambert was upbeat at seeing the skipper back in the claret and blue fold.
Vlaar had a standout World Cup with Netherlands as they reached the semi-finals of the tournament in Brazil.
Several pundits, including Rio Ferdinand, hailed Vlaar as one of the very best players during the prestigious showpiece event.
Vlaar will now return to Bodymoor Heath to begin preparations for the Stoke match, which takes place on Saturday August 16.
Lambert said: "I had a really brief conversation with Ron. No doubt I will sit with him when we have a bit more time when we're back.
"He's positive and raring to go. He's looking forward to getting going. That, it itself, is a plus.
"He loves it here. That's him back now. He's looking forward to the Stoke game."
Lambert was upbeat as he also delivered positive injury updates on Libor Kozak, Christian Benteke and Joe Cole.
He added: "In terms of injuries, Libor is doing great. He won't be fit for the start of the season. Christian won't be fit either. But they are both ahead of their scheduled time.
"Joe is doing great. He started running again. We will see how he is next week.
"But Libor and Christian, as our long-term injuries, are doing really well."
Check out all the details about season tickets.