The midfielder, left, was just one of 16 Celtic players who were on duty in games spread as far apart as Hampden, Botswana and Japan.
It will only be today that they all report back to Lennoxtown, but already Lennon knows he has problems.
While Kayal was limping off at half-time in Geneva, Scott Brown was removing himself from Scotland's friendly against Denmark.
The news on the ankle injury the skipper suffered is good, and Brown believes he will be fit to play against Dundee United, his first competitive game of the season after serving a two-match suspension.
But Kayal is more of a concern and Lennon confirmed: "Beram came off at half-time with an ankle injury, and he will have to have a scan.
"With Scott, we are hoping it is just a precautionary thing. He is still a bit tender from the tackle.
"So, again, it will all depend on what the scan shows, but he was quite confident he would be okay."
Kayal is relieved his injury was not worse after being the victim of a heavy tackle from Chelsea's Didier Drogba during the 4-3 defeat to Ivory Coast.
The Israeli said: "I was in shock when I felt the pain in my ankle because the first thing that flashed through my mind was what happened to Emilio Izaguirre.
"He came in very hard. In a regular game, he would have got a yellow card or perhaps even a red card for something like that.
"He apologised to me afterwards."
As well as checking on his walking wounded, Lennon is being forced to change direction in his search for a new keeper after Grzegorz Sandomierski flew to Belgium for signing talks with Genk.
Spurs' veteran Carlo Cudicini has been linked as a possible target, but Lennon is expected to revisit his attempt to sign Fraser Forster from Newcastle.
Meanwhile, Sion have confirmed that, due to a reduced ground capacity, only 800 tickets will be available to Celtic fans for the second leg of the Europa League qualifier on August 25, which has an 8.30pm kick-off.