Suleiman, a striker, had played internationally on one of Syria's national youth teams. His teammates said he was the father of a 6-month-old baby.
State TV broadcast video of what it said was the hotel. The explosion blew out the windows on the first floor of the building, and shattered glass covered three beds in one of the rooms in which a bloodied duffle bag lay on the floor.
"We were collecting our things about to head to the stadium when we heard the first explosion and the windows were blown off," said Ali Ghosn, a 20-year-old al-Wathbah player.
"Youssef was hit in the neck. We ran out to the corridor when the second explosion struck and I saw Youssef fall down bleeding from his neck," he told the AP in Damascus as some of his colleagues wept.
The attack occurred a few hours before the team was to play the Hama-based al-Mawaair club in Syria's domestic league, which has been delayed several times because of the violence. The game was postponed after the mortar strike.
The nine-team league got under way just last week with all matches scheduled to be played in the heavily guarded capital in front of empty stands.
Assad has tried to maintain an image as the head of a functioning state even as rebels edge closer to his seat of power and targeted attacks suggest rebels may be trying to shatter the sense of normalcy he has tried to portray in the capital.
Also Wednesday, Syrian rebel army chief Gen. Salim Idriss told Al-Arabiya TV that if the Lebanese Shiite militant group Hezbollah does not end its involvement in Syrian towns near the border, "the Free Syrian Army will pound Hezbollah's positions with all the weapons it has."
Syrian activists have said that Hezbollah fighters clashed with rebels in Sunni and Shiite villages just inside Syria over the weekend.
A local Lebanese official in Hermel, near the border, said Hezbollah fighters had entered Syria to protect the Shiite villages. Two of them were killed, he said, speaking on condition of anonymity because he was not authorized to discuss Hezbollah matters.
Lucas reported from Beirut. Associated Press writers Barbara Surk and Bassem Mroue in Beirut contributed to this report.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.