Stefano Pioli has claimed that his Lazio side are not yet ready for Champions League football following their 3-1 playoff defeat to Bayer Leverkusen last night.
The Italian side brought a 1-0 lead with them to the BayArena after Keita's 77th-minute winner at Stadio Olimpico last week tipped the tie in their favour.
However, they encountered a determined Leverkusen as goals from Hakan Calhanoglu, Admir Mehmedi and Karim Bellarabi did enough to help Roger Schmidt's side into the group stages.
Lazio finished third in Serie A last term - a six-place improvement from the 2013-14 campaign - and Pioli concedes that the Champions League represented too much too soon for his ever-improving side.
"Leverkusen were better than us," he told Mediaset Premium. "We lost the game because they played at a higher tempo and we made far too many mistakes.
"The first half was quite balanced really and we were naive, but overall Leverkusen created more, pressed harder and deserved to win.
"This is proof that we probably aren't ready yet for this level, but we also want to grow and we can still do well in Serie A, the Europa League and Coppa Italia. We're preparing to reach this level. We aren't there yet, but have a quality squad and I'm sure we will get back on our feet quickly."
The Champions League and Europa League group-stage draw will take place on Friday, with Lazio in the pot for the latter following their elimination.