That said, the players were visibly exhausted after the match but have had one extra day's rest to prepare well for the first leg. Barcelona's fixtures were certainly a lot more demanding that Real Madrid's, but the Whites did not have an easy run either and hence, a day extra will make a huge difference especially for a match as massive as this one. "If it was the last match tomorrow, than it would be different".
The Argentine returned to training on Tuesday after suffering a thigh injury in Saturday's 2-2 draw with Valencia.
But Barcelona remain stronger now and I expect them to win and take a good lead into the second leg, on their way to the Copa del Rey Final.
The Spanish giants return to Champions League duty against Lyon and Valverde will want Messi fit to play the unsafe French side, who inflicted a first defeat on leaders Paris St-Germain last weekend.
"It is true that sometimes we have had doubts with players and we have waited until the last moment", said manager Ernesto Valverde.
Messi is said to be desperate to play having missed the Clasico drubbing of Madrid earlier this season due to a broken arm. Solari has all of his best forwards, including an in-form Karim Benzema, the quickly maturing Vinicius Junior, and a fully fit Gareth Bale.More news: Bud Light's corn syrup snub riles Iowa farmers
Barca's French forward Ousmane Dembele is unlikely to be fit for the game, as he is still recovering from a hamstring injury.
"I don't think it changes anything", he added when asked how a hypothetical Messi absence could influence proceedings. "We expect the best version of Madrid on Wednesday, as we have seen in recent weeks".
"It is nearly impossible to stop the competitor Messi if he wants to play".
The Argentinian missed training on Monday but was back with the squad on Tuesday evening.
Solari may not start Bale with Vinicius Junior on Wednesday as they usually play on the same part of the field and their presence could make the squad too unbalanced and more vulnerable defensively.
Barcelona weren't keen on risking Messi in the first of their three upcoming matches against their arch-rivals this month and wanted to rest him.