TORONTO -- It looks like Toronto FC's depth is going to be put to the test again.

Last week, manager Ryan Nelsen had to do without veteran defender Danny Califf (stomach virus) and midfielder Terry Dunfield (knee).

Califf was back in training Tuesday, but Dunfield was still missing, awaiting a final verdict on his knee. Defender Richard Eckersley and forward Emery Welshman were also absent.

Eckersley injured his hamstring celebrating the last-gasp goal by Darrel Russell that gave Toronto (1-2-2) a 2-2 tie with FD Dallas on Saturday. Welshman hurt his ankle in the reserve game that followed.

In the locker-room afterwards, Eckersley seemed pessimistic about an immediate return. But Nelsen was more optimistic about his English fullback Tuesday.

"He's just (pre)cautionary at the moment so we're just keeping him out," said the manager. "He's just got a wee tight hamstring."

Asked if Eckersley could play Saturday in Philadelphia (2-2-1), Nelsen said: "Hopefully, yes. We just don't know."

As for Dunfield, who hurt his knee in training a week ago, the club is awaiting word on another visit to a specialist.

"We'll go from there with Terry," said Nelsen.

Jonathan Osorio started for Dunfield against Dallas but gave way to Luis Silva at halftime as the offence stalled.

If Eckersley can't go, Ashtone Morgan could resume his place at left fullback with Russell remaining at right back. Ryan Richter provides cover at both positions.

"Ashtone was really really impressive in the reserve game," said Nelsen.

But Eckersley, a gritty competitor, would be missed.

"He's been fantastic," defender Darren O'Dea said of Eckersley. "I'm gutted for him obviously ... (But) this year we've got players that can step in and do a job."

Morgan started the season at left back, but lost his place after returning from international duty with Canada. Eckersley switched from the right to left flank and Russell came in on the right.

Welshman's ankle was swollen but Nelsen said holding the reserve forward out of practice was just precautionary.

"On this kind of (artificial) surface, with those kind of knocks, it can be a but unforgiving," said Nelsen, referring to the artificial turf under the bubble at the team's training facility.

Califf's return also raises questions, given 21-year-old Gale Agbossoumonde performed well in his place. Nelsen also made a point of complimenting 19-year centre back Doneil Henry for his performance in the reserve game.

"Danny now has to come back," said Nelsen. "That's the realism of professional football -- guys taking their chances. And that's great. Not just Gale, but Justin Braun, Luis Silva."

"It increases the options, which is good," he added.

Silva, for the second game in a row, and striker Justin Braun were difference-makers off the bench against Dallas.

The introduction of the six-foot-three Braun, with Dallas playing without the injured George John, put the Dallas backline under pressure. Braun scored Toronto's first goal and set up the second.

While Nelsen has already shown he goes by performance rather than name or reputation, choosing Agbossoumonde (one career MLS game) over Califf (211) would be an odd selection.

"It's something I couldn't have helped," Califf said of his absence. "I'm just going to get out and try to be good this week, and at least make the decision a tough one."

The 33-year-old Califf is also a former Union captain who has fond memories of his time in Philadelphia, one of his four former MLS teams.

"It's going to be fun. It's going to be interesting to see how they heckle me," he said with a smile. "How creative they get."

Califf spent most of last week "curled up in a fetal position." Toast was about the only food he could stomach.

"It's great not to be feeling like I've got to throw up every 30 minutes," he said.

Notes: As he did all of last week, Nelsen closed practice Tuesday ... Defender Darren O'Dea thought he deserved a penalty late in the game when he was held by a Dallas player in the visitors' penalty box. Video review did not change his mind. "He's actually holding onto me 20 minutes after I've gone down," he joked.