Goals from Ryan Christie and Callum McGregor, either side of Benjamin Tatar’s equaliser, earned the Scottish champions a 2-1 win in the second leg of the first qualifying round tie for a 5-2 aggregate triumph.
While Lennon was more than content with his team’s performance at such an early stage of the season, he was unhappy at the physical approach of Sarajevo who committed a series of robust fouls and had five players booked.
Celtic felt Sarajevo goalscorer Tatar should have received a straight red card from Luxembourg referee Alain Durieux for a dreadful challenge on McGregor but was pleased at the restraint shown by his own team who will now face Estonian side Nomme Kalju in the second of four qualifying rounds they must get through to reach the group stage.
“It was really important we kept our discipline because it’s a big factor in these qualifiers,” said Lennon.
“You don’t want to be losing anyone through suspension. We know how fraught and tense these qualifiers are but the experience of our players will hopefully stand them in good stead.
“Sarajevo were a bit agricultural to say the least. At least one of their bookings warranted a red card. The one on Callum was very high and naughty. At this level, referees sometimes see the game a little bit differently to us. That’s what I’ve learned. You’re better off saying nothing and letting it be.
“But the last thing you want at this stage is any kind of injuries. There will be a few bumps and bruises tomorrow but hopefully nothing significant. We took Lewis Morgan off as a precaution but he’s okay.
“I’m really pleased with the level of performance so far. It’s not perfect by any means - I get that - but for where we are it’s excellent. That’s a 5-2 win over two legs and that’s very good.
“I thought we played excellently, especially in the first half. My only bugbear was conceding the goal when we were in total control of the game and the tie. But Callum came up with a brilliant goal to win the game.”
Lennon reported no update on Arsenal’s pursuit of Kieran Tierney with their anticipated third bid for the £25 million-valued left-back yet to materialise.
But the Celtic manager does expect some incoming transfer activity to be concluded by his club before the end of this week.
“I think we’ll have something in the next few days,” said Lennon. “It may be a right-back, it may be a left winger, it may be a centre forward. We have a number of positions I’d like to strengthen.”