He was among the travelling party that flew to Milan on Monday and trained at the San Siro with his teammates later in the day - although he does not yet have the green light from Barca's medical team to return to competitive action.
Inter need a win to all but book their passage to the last 16 in a group which also includes Tottenham and PSV Eindhoven.
"Argentina have good players constantly but to make things go well, there is still a lot to work", added Zanetti, who won 143 caps for the Albiceleste.
Luis Suarez fired them in front in the 11th minute, yet goals from Jose Angel Pozo and Alvaro Garcia Rivera swung the game in the home side's favour.
"Leo is so big that we have to enjoy him much more".
Ambush on bus carrying Coptic Christian pilgrims in Egypt leaves several dead
Hellyer, senior non-resident fellow at the Atlantic Council and the Royal United Services Institute in London. Church spokesperson Bouls Halim told The Associated Press news agency the death toll was likely to rise.
Barcelona sparked confusion by omitting Messi from the original squad list for the game published on social media, only to amend it minutes later with their captain included.
Ernesto Valverde, Barcelona's head coach, has selected Rafinha, who scored in El Clasico, to deputise for Messi in the previous four games.
The Catalans sit top of Group B after winning all three of their matches so far.
FC Barcelona goalkeeper Marc-Andre ter Stegen (1) during the match FC Barcelona against Real Madrid, for the round 10 of the Liga Santander, played at Camp Nou on 28th October 2018 in Barcelona, Spain. We know we have to improve, but the important thing is the goal difference.
"We've always said we can play against anyone, and that still holds true".