Pique played for United from 2004-08 after coming up through Barcelona's youth academy.
Since winning its fifth and last European Cup, Barcelona failed to advance past the quarterfinals in each of the last three seasons.
Juve can still seal the title at home next weekend when they host Fiorentina, or even sooner if Napoli fail to beat Chievo on Sunday.
Barcelona have lost only one home game in the Champions League in 10 years but United will take hope from their last 16 comeback against Paris Saint-Germain, when they overturned a 2-0 first-leg defeat to go through. "I don't know to what extent because he has been out for four weeks", Valverde said.
The return leg is at the Nou Camp on Tuesday (20:00 BST kick-off).Referring to his aerial challenge on Messi, Smalling added: "I didn't realise at the time that I'd actually caught him like that."Suarez [came up to me] after the game as well".
"We paid a little for our inexperience", said Allegri. Live streaming is available on beIN Sports Connect, which you can access with your cable or satellite subscriptions, either online or through the beIN Sports Connect app.
Valverde will make a late decision on starting with France winger Dembele or former Liverpool attacker Philippe Coutinho but hinted he would leave the former Dortmund winger on the bench. He played 70 minutes the other day, which was what we had planned.
AC Milan consolidated fourth place with a 1-0 win over Lazio.
"But again there are two legs, you will have to go away in the second game".
Replays showed that Smalling got the ball after leaping through the air to intercept it but the Englishman's arm caught Messi in the face.
Juventus had a chance to equalise in stoppage time but full-back Mattia De Sciglio headed wide from a free-kick.
"He played his part in us putting them under pressure".
Barcelona coach Ernesto Valverde was happy with his youngsters for their 0-0 draw with Huesca. He said: 'With just six days between games I knew I had to do something. He made an immediate impact, helping the club sweep the league, Copa del Rey and Champions League, scoring seven goals in Europe.