NEIL Lennon may have to go back to the defensive drawing board after ruling Derik Osede out of this weekend’s season opener against Derby County.

The Wanderers boss had planned to pair his summer signing with Dorian Dervite until he limped out of the 2-2 friendly draw with Charlton Athletic.

And his options were limited further on Saturday as David Wheater limped out of the development squad game at Southport.

Tim Ream – back in the camp after international duty over the summer with the US – is now set to be drafted in, leaving Lennon with some remedial work on his hands.

“Derik and Dorian have played together in the majority of our games so far so we’re going to need to work on something different now,” he told The Bolton News. “In that respect, having Tim back from the US is good timing.

“It isn’t a serious injury – but I’m not going to lie and say it isn’t a blow.

“These things happen and you have to deal with them but we could certainly have done without it.”

Derik faces three weeks on the sidelines with an ankle strain after landing awkwardly early in the second half on Friday night.

And while Lennon concedes there is little he can do about the Spaniard’s absence, he has warned his squad that he expects them to report for duty with much more regularity than they did last season.

“I told to the players after the game – just don’t get injured,” he said.

“That was a trauma injury, so there’s not a lot we can do about it but last season there were too many niggles and strains, and I’m not having it this year.”

Wanderers twice led against Charlton through Darren Pratley and Liam Feeney but were pegged back by Lennon’s former Celtic charge Tony Watt – the player who scored the winning goal for him in a memorable win against Barcelona in the Champions League in November 2012.

Lennon was nevertheless happy with the final performance of pre-season, and especially the way his side reacted in the second half after Derik’s injury, which was quickly followed by Charlton’s second equaliser.

“I thought we were off the pace in the first half but the likes of Mark Davies, Darren Pratley and Zach Clough needed the game time,” he said.

“Second half I thought we were really good – a bit unfortunate to concede the goal – but going forward we were far more aggressive, full of energy and we created some very good chances.

“We experimented a bit with the formation in the first half but then we brought Liam on and he gave us that bit of extra zip.

“Charlton have invested heavily and they are a pretty good side now, they’ll be up there.

“So in terms of a workout, knowing what we are coming up against, I couldn’t have asked for much more really. I’m very, very pleased.”