The injury bug has struck Toronto FC on the eve of its first-ever CONCACAF Champions League game.

On Tuesday midfielder Amado Guevara missed training for a second-straight day with a rib injury. The Honduran was substituted after 22 minutes in Saturday's 3-2 loss to the Columbus Crew and went for x-rays on Monday, but no update has been provided.

The Reds also trained without defender Adrian Serioux for the second-straight day. Serioux also suffered a knock against the Crew and rode the stationary bike on Monday while the rest of the team ran drills. Coach Chris Cummins confirmed the injuries to Guevara and Serioux, adding that Canadian defender Nana Attakora will be unavailable for selection on Wednesday night.

"Nana (Attakora) is going to be out, he is struggling with his hamstring and it is going to be a couple of weeks for Nana," Cummins said when asked about the injuries ahead of Wednesday night. "But I will always put out the best team. The best 11 will always start and it is up to the other lads to go and fight for the spots. There is a lot of games coming up, but we want to go win every game."

The first leg of the Champions League Preliminary Round against Puerto Rico Islanders at BMO Field will be the first time the two clubs have faced each other. The Islanders (9-5-8) play in the USL First Division, the same league as both the Montreal Impact and Vancouver Whitecaps. The Islanders dropped its weekend match to Vancouver, but remain in a three-way tie for top spot.

"To be fair we have some video evidence. ProZone has done their work and we have had a look at them," Cummins said on Monday. "It is not a case of us going in and not knowing anything about them. They are a decent team: big, strong, athletic -- they will probably look to counter and play well off set pieces; which is what a lot of the lower league teams try to do."

Both USL teams gave Toronto FC fits in the Nutrilite Canadian Championship, with Toronto scoring a miracle five-goal victory over Montreal in the final game to win the title.

"We definitely do not want to go in to the game trying to get a 6-1 result," Cummins joked. "In any home games you do not want to concede. The away goals count so you need to be nice and solid at home then go away and be nice and solid away as well. A 1-0, two-nil, nil-nil, it is massive we do not concede."

A positive for Toronto ahead of the match will be the return of midfielder Sam Cronin. The rookie has been away for the last month with the United States squad at the Gold Cup but should be available for selection on Wednesday.

The game on Wednesday is also the first of three in seven days for the Reds, who play MLS rival New England on the road Saturday before the return leg in Puerto Rico on August 5.

"The most important game is the next game, and it is Puerto Rico. We need to prepare for that."

The winner of the two-game preliminary round between Toronto and Puerto Rico will advance to the group stage of the CONCACAF Champions League, which begins on August 18, 2009.