Driver, 25, has signed on loan for MLS outfit Houston Dynamo until the end of the season, when he will complete a permanent switch.
But despite having four months left to run on his contract and recently showing signs that he may be hitting top form after two years of injury woes, McGlynn admits relieving the club of Driver's weekly wage - believed to be in the region of £10,000 - was an opportunity not to be missed.
Hearts were issued with a winding-up order by HMRC late last year over a unpaid £450,000 tax bill and have also been forced to negotiate a repayment plan for another due sum totalling £1.75million.
McGlynn said: "From the manager's point of view you always want as many players as you can, but it probably made sense.
"I think everyone would realise that Andrew is one of the big hitters with regards to salary.
"The football club is trying to cut back and he had an opportunity to do something that he felt was right for him and both parties came to an amicable agreement that left him do his part going to America.
"It's not easy because I've known Andrew for a long, long time, probably from the Under-14s or 15s when we were down training at Musselburgh.
"The pinnacle would have been winning the Scottish Cup on May 19 last year. It's great for him but it would have been nice to have kept him until the end of the season.
"The people above are letting Andrew go because it is a burden on the football club."