The former Manchester City man picked up a knock in a narrow loss to the Championship side, with the defender playing just over half an hour of football
Former Manchester City centre-back Lescott came on as a half-time substitute after recovering from a calf injury that had sidelined him since he featured in a behind-closed-doors friendly against Bury last month, but limped off 10 minutes from time at the City Ground.
Fellow defender Pocognoli then had to come off in the closing stages as Championship side Forest secured victory in Stuart Pearce's first home game in charge since returning to the club courtesy of new signing Matt Fryatt's first-half strike.
Albion head coach Alan Irvine would have been encouraged to see captain Chris Brunt make his first appearance in pre-season after the midfielder recovered from a groin problem to feature for the last 18 minutes.
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New signings Andre Wisdom, Pocognoli, Chris Baird and Craig Gardner all started for Albion, while Claudio Yacob and Craig Dawson were also included from the start despite uncertainty over their futures at the club.
There was early drama when referee Andre Marriner was replaced due to injury and Forest were then in front after 25 minutes.
Winger Chris Burke was the architect, crossing for fellow new boy Fryatt to slot home after Belgium defender Pocognoli had slipped over.
Jonas Olsson spooned a Jamie Paterson cross just over his own crossbar and Michael Mancienne headed an Andy Reid corner over as Forest pressed for a second just before the break.
Lescott and Victor Anichebe replaced Olsson and Yacob at the break and Forest almost doubled their lead just after the interval, but Ben Foster thwarted Reid from point-blank range with a fine save.
The Premier League side started to show more of a threat, with Graham Dorrans seeing his left-footed strike from outside the penalty area tipped wide by Karl Darlow and Gardner heading wide seven minutes into the second half.
Fryatt came close to a second goal when he side-footed just wide, then Darlow kept out a venomous Anichebe strike before the former Everton striker had a header cleared off the line.
Albion continued to press, but were unable to fashion an equaliser and the sight of Lescott and Pocognoli limping off will have concerned Irvine.