TORONTO -- The first sign something was amiss Tuesday was head coach Greg Vanney lining up on defence in training.

Vanney, a former U.S. international fullback, is no slouch at age 40. But the fact he was making up the numbers demonstrates just how much Toronto FC (1-1-0) is hurting in the backline ahead of this weekend's road game against Real Salt Lake (0-0-2).

Fullback Justin Morrow is suspended pending an appeal of his red card. Centre backs Steven Caldwell (Achilles and calf strain) and Damien Perquis (calf strain) both missed practice Tuesday.

Reserve fullback Mark Bloom has quad soreness while backup centre back Eriq Zavaleta rolled his ankle and was in a walking boot last week. Marky Delgado, who offers depth in defence, is away with the U.S. national team.

Caldwell, Bloom and Zavaleta are questionable. Perquis is seen as probable for Sunday's game in Utah.

And this is with the benefit of a bye week.

Consider that star midfielder Michael Bradley and Jozy Altidore are with the U.S. national team in Europe and Toronto has holes all over its starting 11.

"Everybody's going to be in play for this weekend in terms of options," said Vanney. "We'll assess how the injured guys progress over the course of the week."

The injuries to Caldwell and Perquis may have been triggered by training on turf and playing on grass, Vanney suggested.

A back four of Ashtone Morgan, Perquis, Nick Hagglund and Warren Creavalle looks to be Vanney's best option in Salt Lake City. Given Creavalle is a work in progress at fullback, Morgan is rusty after falling off the radar last season and Hagglund is a second-year pro, that puts a lot on the broad shoulders of Polish international Perquis, who will be playing his third MLS game.

Toronto also had TFC II defender Clement Simonin, a classy French rookie drafted out of North Carolina State, at practice Tuesday. He will have to be upgraded to an MLS contract from his existing USL deal if he is promoted to the first-team roster.

RSL is also without top talent. Goalkeeper Nick Rimando (U.S.) and midfielder Luis Gil (U.S. under-23), defender Elias Vasquez (Guatemala) and striker Alvaro Saborio (Costa Rica) are away on international duty. Unlike top leagues in Europe, the MLS does not take a break during international dates.

Toronto did get a break with Italy electing not to call up forward Sebastian Giovinco. But Real Salt Lake gets to keep U.S. international midfielder Kyle Beckerman.

Collen Warner and Luke Moore are expected to step in for Bradley and Altidore, respectively.

"That's fair to say. We don't have too many other options," Vanney said dryly.