Connor Essam's move to Leyton Orient is complete after the Sky Bet League 2 side agreed a fee with non-league Dover.
Midfielder Danny Guthrie has become Blackburn's third signing of the summer.
The extent of Dundee United's final debt repayment bill depends on their transfer income in the next three windows, the club have revealed.
United issued more details about their recent bank settlement in their annual accounts for last season, which showed a £319,000 profit - their fourth in five years.
The club could repay as little as £1.7million of a £4.7million debt to the Bank of Scotland, but could pay close to the full amount if they sell some of their top-rated young players.
United revealed earlier this month that a group of fans would pay an initial sum to the bank to transfer the debt, although the details were confidential. United paid £175,000 in interest fees during their latest financial period, which ran to June 2013.
A club statement read: "Since the 2013 accounts were completed, the club reached an agreement with its bankers to close off its debt position.
"The negotiated terms included a payment of £1.45m to settle all borrowings and accruals due to the bank at the date of the agreement, with any further payments contingent on the receipt of any transfer proceeds received up until 31 August 2015, during which time the bank will be entitled to a reducing percentage share of these proceeds.
"The total amount due to the bank at the date of entering the agreement was £4.7m. The potential full payment under the terms of the agreement will be between £1.7m and £4.1m, depending on the club's performance in the transfer market."
United's financial performance was helped by more than £500,000 savings in wage costs and a £595,000 transfer profit, thanks to the sale of Johnny Russell to Derby.
Turnover increased to £5.4million and the wages-to-turnover ratio dropped from 76 per cent to 61 per cent.