Mark Warburton is chasing a mystery striker in a bid to bolster his Rangers forward line for a crack at the Premiership title.

But defender Oguchi Onyewu is unlikely to be offered a deal after spending time with Warburton’s squad in South Carolina and turning out against Charleston Battery.

The 34-year-old featured twice during the 2-1 win at the MUSC Health Stadium on Wednesday night at the end of a ten-day trial period, but he has not done enough to convince Warburton he should become his ninth signing of the summer.

Read more: Michael O'Halloran: Charleston trip will help bring out the best in me for Rangers

The Gers boss also has a number of targets that he is continuing to monitor as he looks for another defensive recruit and SportTimes understands that Onyewu will not be given a deal as he pursues other options in the States.Glasgow Times: Rangers manager Mark Warburton

Warburton also remains in the market for a forward to provide competition with Martyn Waghorn and Kenny Miller through the middle next term.

And he hopes the work that Head of Recruitment Frank McParland is putting in will soon pay dividends as he looks to get another deal done with the big kick-off approaching.

Read more: Harry Forrester: Pain of missing season finale will spur me on this term at Rangers

Warburton said: “We are looking at that fourth choice centre half and we are looking at the striking position as well and if we get these done we will be OK.

“It’s not simple sometimes. They want £2million, you are prepared to pay half a million and you try to meet somewhere in the middle.

“We might spend money or we might not do. The trick is to get the work down under the radar as Frank has been doing,

“We have been linked to so many strikers and that’s good because the real targets have not been mentioned.Glasgow Times: Mark Warburton

“The one we want is one you haven’t dug up yet but I have no doubt you will keep on digging.”

Warburton saw his side in action for the first time this term as Rangers ended their South Carolina trip with victory over Charleston Battery on Wednesday night.

A severe thunder and lightning storm forced the match to be delayed by almost 90 minutes before a tough encounter in the stifling Holy City heat.

Defender Danny Wilson suffered a facial injury early on and needed stitches before goals from Josh Windass and Harry Forrester clinched a deserved victory for the Gers.

Warburton said: “I spoke to their coach and they are used to that so they reduce their warm-up time. It was just a case of being patient.

“We just tried to rehydrate the guys who were coming later in the game and make sure there were no injuries.

“Everyone got time. Some people like Tav got 70 minutes others like Kenny played 45, it was just what we felt was appropriate for the training week.”