Cristiano Ronaldo was nursing an ankle problem and could not continue as Juventus were denied victory by a last-gasp Felipe Caicedo goal in a 1-1 draw at Lazio, Andrea Pirlo said.
Portugal star Ronaldo opened the scoring after 15 minutes at Stadio Olimpico to net in his first four league games of a season for just the third time, having also done so in the 2009-10 and 2014-15 seasons.
With 27 goals to his name in 2020, no player in the top-five European leagues has more in the calendar year, but his withdrawal with 14 minutes of Sunday's clash ultimately proved a pivotal moment.
Explaining why Ronaldo, who did appear to hobble as he sat on the bench, was taken off, Juve coach Pirlo told DAZN: "Ronaldo is a key player not only for us but for all the teams where he played, he had an ankle problem and he was forced to leave.
"Those who entered the pitch did well, [but] we had problems to hold the ball and manage certain types of plays."
Ronaldo had three shots on target from five attempts and also crashed an effort against the post for a Juve side who continue to trail early leaders Milan, three points adrift of Stefano Pioli's team ahead of the Rossoneri's clash with Verona later on Sunday.
The Bianconeri are unbeaten through seven games for the eighth time in the past 10 seasons, but Pirlo warned his side that titles are decided on moments such as late levellers.
"We played a great game, they never had a shot on target," he added.
"Championships are won if we take care of every detail, we mismanaged the ball in the final 10 seconds and they scored the equaliser."
Lazio were hindered by the absence of star striker Ciro Immobile who alongside Lucas Leiva and Thomas Strakhosha was absent after they reportedly returned inconclusive tests for coronavirus.
Caicedo entered the fray to replace the largely ineffective Vedat Muriqi after 54 minutes and his stoppage-time leveller was the fifth time since the start of last season he has scored after the 90th minute – the most in Serie A.
"I have an exceptional rapport with Ciro, he wished us all the best and we missed him today, but he is always present even when he’s not physically here," Caicedo said.
"With this determination and refusal to give in, we can go far. We can continue to do what we did last season, with the attitude we showed last week against Torino and again here."
Head coach Simone Inzaghi, whose Lazio side have gained 33 points from a losing position since the start of last season which is more than any other team in the top five European leagues, paid tribute to the goal hero.
"Caicedo is a great player, a wonderful person who after five or six months was already adored by everyone," Inzaghi said.
"I asked the club, and they immediately agreed, to keep him, as he was the ideal player to complete the front line."