Kieran Tierney completed a move from Celtic to Arsenal for a fee of £25million on deadline day to the despair of Hoops fans - but Mikael Lustig and Patrick Roberts have applauded Tierney, posting good luck messages.
And he admitted that players could leave before anyone else arrives. Obviously it was protracted because we couldn't agree a deal.
"He is finding it hard to get in the squad at the minute but it's very early days and once the season goes on you will imagine Scott will make a contribution", said Lennon, whose side travel to Motherwell on Saturday.
"It's the first way for us to achieve our targets and objectives to be in the top four, but we know it's going to be hard".
New signings Christopher Jullien and Boli Bolingoli still look like they are adapting to the style of play in Scotland, Bolingoli especially. I don't have ones and twos and threes, I have people competing for the position.
"We're delighted Kieran is joining us", he said. That will all depend on price, wages and the quality of the player.
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He said: "I have a friend at Juventus in Cristiano Ronaldo, he helped me a lot while I was there, both personally and on the pitch".
"Kieran is the latest one and obviously Jamesy (Forrest) and Callum and now Mikey Johnston are making significant contributions to the first team. I don't think our fans are expecting us to find like for like immediately".
Europe is where we could see Celtic come undone, and Lennon will be hoping to secure a win on Tuesday night against CFR Cluj in the Champions League 3rd qualifying round, second leg.
When told this was only 4cm away from Aubameyang's best the Scottish defender smiled and said: "I will try and beat that".
'Now I just feel was the right time to take a step on.
"I'm not complaining, we have to get on with it, but it's a big ask for them to turn things round very, very quickly and play to the same levels in a 48-hour period".