Birtles: He was a first class man
The 53-year-old passed away just hours after the Silkmen's League Two match at Notts County on Tuesday night.
And Birtles, who played in the same Grimsby Town team as Alexander in the late-1980s, described him as a "first-class football man."
He said: "Keith was the first player to welcome me into the Grimsby dressing room when I first went there, which meant a lot to me at the time.
"I was an experienced pro by that stage, but still when you move to a new club it is nice to be made welcome and he was the one who did that.
"He was an ambitious, passionate guy. He always had a smile on his face; was always laughing and joking. He was basically just a genuine, nice bloke. That was what he was."
Birtles added that whole football world will be saddened by the news: "I suspect that people who did not know him will quickly realise what a nice bloke he was, because I expect that many people will be saying exactly that over the next few days.
"It was a privilege to have played with him during a very enjoyable finale to my career. He was a first-class football man."
Others to pay tribute to the likeable boss included his assistant manager at Macclesfield, Gary Simpson, who could take charge of the team if their League Two match with Hereford on Saturday goes ahead.
He commented: "He (Keith) was a larger than life character – an honest man, a splendid man and will be missed by not only football people but people in all walks of life.
"He was an absolutely superb human being."
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