Riewoldt had not played since round three but booted 1.4 and took six marks in an encouraging first hit-out for the Saints in their 14-point win over the Brisbane Lions at the Gabba on Saturday night.
Lyon said it was good to have his captain back on the field.
“It puts everyone more at ease,” he said.
“It’s great for football; I think we love our great players on the paddock and he just happens to be one who plays for St Kilda.
“Clearly he makes us a better team but I thought we kicked to him way too often early.”
The Lions held a 16-point advantage at half time, keeping the Saints goalless in the second quarter.
Lyon said Riewoldt improved as the game went on, kicking a crucial goal in the final quarter.
“He really started to play with real movement and presence,” Lyon said.
“He was clearly being targeted but that’s OK, he’s a champion and he can respond.
“To go back and kick the goal gave us a real team lift; probably the message is, don’t unsettle champions.”
Lyon said he was pleased Riewoldt played more than 80 minutes of football.
He was benched late in the game after cramping.
Justin Koschitzke was a late withdrawal due to an ankle injury while star midfielder Brendon Goddard contracted a virus before the game.
“He (Goddard) was playing even up until late so it was a late decision, but it was a conservative decision and in the end the right decision,” Lyon said.
Lyon said he was nervous going into the Gabba clash, with the Lions fielding 20 players from their round 10 win over Collingwood.
He said he expected a week of negative publicity to spark the Lions into action.
“The amount of adverse press they had and negativity and questions not only about their football but internal politics really was a combustible lot of variables that came together,” Lyon said.
Lyon said the St Kilda players were their own worst enemy in the first half after leading the disposal count (205 to 194) and inside 50s (28 to 23).
“We had 28 entries to half time and had three goals - and that was the frustrating bit,” he said.
“We spoke about what we needed to do, just make them defend a little bit more, a little bit more forward structure, keep some shape, and from there I thought we really got to work.”
