Losada, who scored in last Wednesday’s 6-0 Women’s FA Cup quarter-final win over Leicester, is struggling with an ankle knock.
However, Stokes – who missed the win over the Foxes through injury – is in contention to return.
With City affected by injuries to several key defenders, Taylor will also be boosted by the availability of summer signings Alanna Kennedy and Ruby Mace who were both ineligible to play against Leicester
“Vicky is going to struggle potentially with the ankle injury she sustained (against Leicester),” the manager confirmed.
“We are waiting on the image to come back so we can assess it properly but it’s looking unlikely. Demi is back in training for us today, so it’s kind of one in and one out.
“And then we have Alanna and Ruby who can come back into the fold.
“The good thing is that Keira (Walsh) came back and got good minutes under her belt on Wednesday night.
“It was really good to get her back and I thought she showed good leadership against Leicester and came in seamlessly, which is hard when you’ve been out for as long as she has.
“I thought the way she handled the final half hour on Wednesday was top.”
Roebuck has been side-lined so far this season with a calf injury while Houghton is recovering from an ankle setback
“Ellie has had a minor setback in her rehabilitation. Hopefully that hasn't pushed her back too much,” the boss added.
“Steph is out of her boot now which is good but she is still using crutches. It’s a bit of a boring rehab for Steph because what she can do is minimal in terms of that type of injury.
“But I think it will be a few weeks before we start discussing their next step.”
City will be looking to build on Wednesday’s impressive cup win and bounce back to winning ways in the league after losses to Spurs and Arsenal.
However, the boss said he was under no illusions as to how demanding opponents West Ham will prove to be with the Hammers lying in seventh place in the table - just above City.
“I’m expecting a tough game,” Taylor added.
“They will make it difficult and try to protect space as much as possible.
“They have some fluidity with the manager (Olli Harder) being there a while and players remaining and changing a few.
“Their results have been good so far. They've stepped up in that respect, so we are expecting a tough game.
“For us, we want a similar performance to the second half against Leicester.
“The important thing for us is to try and get a couple of wins on the board before the next international break.”