Kenny Jackett has applauded the Pompey wing wizards which have inflicted a sizeable selection dilemma.
Harness’ dazzling display was the inspiration behind the Blues’ 2-1 victory over Northampton in the Leasing.com Trophy on Tuesday evening.
The summer recruit bagged his fifth of the campaign and also created Leon Maloney’s leveller during an eye-catching showing.
It ramps up the competition in the wide areas, with Ryan Williams and Ronan Curtis also enjoying excellent form at present.
Curtis has roared back to his best, registering five times in his last seven outings, while Williams netted at Rochdale last month and been involved in a number of recent goals.
And Jackett is delighted with his attacking options.
He said: ‘Marcus put on a very good performance against Northampton and scored a terrific winner as well.
‘Last season we had two strong wingers in Jamal Lowe and Ronan Curtis and then two lads – Andre Green and Dave Wheeler – behind those.
‘When they went back, we couldn't really replicate the same ability in the second half of the season.
‘In Williams, Harness and Curtis, we now have three which are our own and hopefully we can get the best out of them.
‘They are all in form and each bring something slightly different. Williams has been a good player in a short space of time and Curtis did well last year.
‘Rather than loans, we have three of our own players who will be here all season. Hopefully we can get the best out of them, that is really important.
‘It is quite a strong position for us and we have to keep them going, keep them topped up with games. Whichever two play, there’s a good addition coming off the bench as well.’
Harness had been missing out, but was promoted from the bench for cup games against Altrincham and Northampton in the past week.
Jackett added: ‘All three wingers have been a real strength for us in recent games and a key to some big wins.
‘With Marcus pushing them during the course of the season, I do think all three can be effective for us right the way through.’