The forward began training with the club last Thursday and is a free agent having been with Queen of the South last season.
Knight, who watched Saturday’s win over Forest Green from the stands at The Northern Echo Arena, will pen a contract today and will be in the squad for Saturday’s trip to Bath City.
Manager Mark Cooper hopes the former Brighton ace, who will turn 28 on Thursday, will be able to recapture the form which saw him propel the Seagulls to promotion from League One in 2003-04.
Hackney-born Knight scored 27 goals that season, but has since endured a nomadic career, with Darlington becoming his ninth club in five seasons.
He arrives as Richard Offiong goes back to Carlisle with an injury. However, Cooper would not have sought an extension to his loan.
Meanwhile, striker Liam Hatch has admitted he is finding the rough treatment at the hands of opposing defenders frustrating, as is the lack of sympathy from referees.
Saturday’s 3-0 win saw Hatch repeatedly on the end of tough-tackling that referee Peter Bankes failed to punish.
But the Merseyside official frequently awarded free-kicks against the tall Quakers forward.
“I think referees see me as a big character and think I should be a bit stronger,” said Hatch. “Sometimes you get fouled but you don’t get the free-kick – you’ve just got to pick yourself up and
“It’s very frustrating. You want to do the best that you can but when you’re getting fouled you can’t do that.
“I know a few of the Forest Green lads and I’ve played with a few of them before.
“I’ve been around this league for a while now – it’s a battle and they know that when they play against me they’re going to get a battle.
“But it’s a team game and as long as I’m getting attention it means someone else isn’t so I suppose it works out.”
Hatch is struggling for goals at the moment with his strike in the fourth minute of the opening day win over Newport County remaining the only occasion he has beaten the keeper.
But Cooper was pleased with the forward’s work-rate on Saturday, saying: “The team worked hard, they ran their socks off, and Hatchy had come to a standstill by the end. I expect that from him
“That’s how I want him to be, I want him to be horrible, I want him to be a handful.
“You judge players by asking would you like to play against him? When Hatchy is on top of his game you wouldn’t like to play against him.
“He’s big, awkward and gangly. Sometimes he gets things off referees and sometimes he doesn’t but we need him to put that effort in every week because we get a lot out of his hard work.”
Hatch is confident he will soon be back among the goals, saying: “I had a couple of chances on Saturday that maybe I could’ve put away.
“It’s just about getting into the right areas and the goals will come.
“I just need to keep getting on the end of crosses and connect with them a little bit better.”
Meanwhile, a Darlington XI play at Spennymoor Town this evening (ko 7.15pm).