The manager's version of events, as reported by freelance journalists James Horncastle and Adam Digby, contradicts previous reports; it was understood it was a club decision to drop Icardi from the Europa League roster.
There have been drawn out contract talks between the Argentinian striker and Inter, which have been met with growing impatience from Spalletti. Icardi was stripped of the captaincy earlier Wednesday, with goalkeeper Samir Handanovic inheriting the skipper's armband.
"Taking the armband off Icardi was a difficult and painful decision, but we know his worth," Spalletti told the assembled media. "However, we took it together with all of the club's components involved. It was done exclusively for the good of Inter."
Icardi, 25, has scored nine times in the current Serie A campaign, but his last goal in that competition came in mid-December. He also found the net on four occasions in the Champions League group stage, but Inter finished third in their quartet and dropped into the Europa League knockout rounds.
Inter visit Rapid Vienna in the first leg of their round of 32 double-header on Thursday before the reverse fixture is contested at San Siro one week later.
"All of our attention is now on tomorrow's game," Spalletti said of the opening clash in Austria. "One that is extremely important."