Watson missed Friday night's clash with Collingwood with an ankle injury, which was initially diagnosed as a two-week complaint.
Coach Matthew Knights said while McVeigh was a definite inclusion after serving a one-match suspension for missing a training session, Watson remained in doubt.
"Jobe isn't guaranteed for this week. He would have to train on Friday as we haven't got a session on Thursday," Knights said.
"He would have to train really well. He's made good ground and is running well in straight lines and has built his pace up, but he still hasn't done any off-line work at the moment.
"That will come later in the week. He's not a guarantee and I won't be playing him unless he's 100 per cent fit."
Knights said McVeigh didn't play for the Bendigo Bombers on the weekend as he was a little sore after a self-imposed punishing training regime.
However, he said he was fine to play this weekend "and pretty keen to do well".
Knights also indicated young defender Michael Hurley could come into the side after a spate of strong performances in the VFL. Forward Angus Monfries will miss the next two weeks with a minor hamstring strain.
Knights said the Bombers would research footage of the way the Swans have played against them in the past, and of how they set up without retired forward Barry Hall in the lead up to this game.
He said the absence of Hall meant there was a degree of unpredictability about the side.
"Without Barry there, it's a different set up because he and Michael O'Loughlin have been amazing players for Sydney for such a long period," he said.
"They have many other threats and are quite competent right across the ground.
"With Barry and O'Loughlin in, because they're such great players, the team is going to go to them a lot. Without Barry in, they become a different kettle of fish because they've got a number of other options, which gives them a bit more unpredictability.
"We've got to be mindful of that, that you can't let other players get under your guard, whether it be Heath Grundy, or Jesse White kicked eight goals in the reserves last week.
"You've got to treat every player on their merits, and every player in this league has their fair share of talent.
"You shouldn't be underestimating anyone or you tend to get bitten a bit."
Knights said the Bombers were looking forward to taking on the Swans, who are placed just one game behind them on the ladder.
"It's a big challenge for us to go up to the SCG and play the Swans, who are a very strong team," he said.
"They will make you earn everything and it's going to be a great contest, particularly for us to bounce back.
"It was a fairly disappointing result last week. Collingwood clearly outplayed us in periods of the game, and they got away.
"We're looking to bounce back. The mood has been really good this week. We looked at the vision on Monday and went through the gory parts of it and reviewed the areas we could have been much better in.
"We got back on the bike and really tried to get the mood up and train well this week."
