AFC Bournemouth have signed Christian Atsu from Chelsea on a season-long loan deal.
Midfielder Miguel Pallardo has signed a new one-year deal with newly-promoted Hearts while Danny Wilson leaves.
Lennon is actively seeking to sign players but, with his team still in four competitions, he is not overly concerned about adding to his pool.
And with the Champions League clashes against Juventus to look forward to, Lennon appears confident of holding on to his top players despite contract offers remaining unsigned by striker Gary Hooper and midfielder Victor Wanyama.
Lennon, whose side moved seven points clear in the Clydesdale Bank Premier League with victory at Dundee on Boxing Day ahead of their trip to face Hibernian on Saturday, said: "We are far more relaxed about it probably going into this year than we have been for quite a while, but we have earned the right to be in this position.
"The players have played beyond their expectation levels, but we are only halfway through the season.
"I just let it ride. I've spoken to a number of the players over the last week or so just to say: 'Look, there is going to be a lot of speculation. As far as I'm concerned, you won't be leaving the club and just concentrate on what you're doing'."
Lennon feels his players are happy to remain at Celtic Park.
The former Celtic skipper said: "Why wouldn't they be? We are in four competitions. We are in the last 16 of the Champions League. We are top of the league, the semi-final of the League Cup and the last 16 of the (Scottish) FA Cup.
"Why would you want to give that up now having worked so hard to get there in the first place?
"In four or five months' time maybe they can reflect on the season and look to the future again but for the time being they may never get this opportunity again.
"I don't think there are many other clubs that can offer that and if they can, then they will be cup-tied anyway.
"What's the rush? Why go now when they can maybe go further down the line?
"Or maybe we are all pre-empting things. Maybe the players don't want to go anywhere, the majority of them seem to be very, very happy here."
Lennon admitted the club were "heavily involved" in the process of recruiting with the focus remaining on signing younger players who can be re-sold rather than the previous trend of signing high-profile players in January such as Roy and Robbie Keane.
Lennon, who has lost James Forrest and Charlie Mulgrew to minor injuries ahead of the Easter Road clash, added: "Every window you are always looking to come out stronger than you went into it. It's not always possible but that's what we will try to do.
"January is a time where clubs want to improve their squads but other clubs don't want to let their players go.
"I'm not too sure how much business will be done in January.
"We are looking to enhance the squad if we can. We have options we are looking at, whether we can get them over the line is another thing."
Lennon was unable to say whether any fringe players might depart or go out on loan, although he dismissed reports that Crystal Palace were keen on Paddy McCourt.
On the general prospect of players leaving, Lennon said: "There might be a possibility but that's something we haven't had time to think about. We will look at that over the next few weeks.
"Paddy has had his injuries but he is an important part of the squad and he might play his part over the next few games."
Celtic face a Hibs side who drew 2-2 at Parkhead earlier in the season and remain in the top four of the SPL despite taking one point from their four most recent matches.
Lennon said: "I think Pat (Fenlon) has made huge strides in turning things round at Hibs.
"They were languishing at the foot of the table for the majority of last season. They got to a cup final, albeit it ended disappointingly.
"But the progression they have made under Pat this season has been tremendous. They have been more or less there or thereabouts in the top three or four all season.
"He has turned around the character of the squad, I think he has recruited well, and in (Leigh) Griffiths they have a player who has been very consistent this season.
"Easter Road is a great fixture, Celtic-Hibs, and the players are very much looking forward to going there and playing. But it won't be easy."
Meanwhile, Lennon revealed Steaua Bucharest had been pencilled in as opponents for a friendly at the end of their week's training camp in Spain during the SPL winter break next month.