The Tynecastle club have parted company with manager John McGlynn after his side were shot down 2-0 by Lennon's men in Paisley on Wednesday night.
The defeat left Hearts sitting second bottom of the Clydesdale Bank Premier League, but Lennon claims the former Raith Rovers boss was doing a good job under severe financial restraints that had already seen many of Hearts top earners depart.
He said: "It's disappointing because I don't think John got enough credit for the difficult job he had at Hearts.
"It's a club that is going through financial strains at this minute in time, but when your club suffers and your results suffer, it is the manager whose head who is on the line.
"However, I thought he was doing a terrific job. There's a lot of kids that are getting valuable experience and that is only going to set Hearts up for the future.
"But we've been through this ourselves. Bleeding younger guys in, you are going to get that inconsistency and hit lows."
McGlynn is the ninth man to be given the job of managing the Gorgie club on a full-time basis since owner Vladimir Romanov bought them in 2005.
But Lennon, whose side will face the Jambos again at Hampden on March 17, is wary about just who will want to be the 10th.
"There have been many there before John, prior to him getting the job," said Lennon. "I don't like speaking about other clubs but looking at the amount of managers Hearts have been through the past number of years, any future employee has got to be very careful and do their homework first."
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