In his eagerness to play for Durham in their first Lord’s final on Saturday, Stephen Harmison may have caused another injury that is jeopardising his participation in that match.

Last night, the pace bowler was awaiting the results of a second scan on his back, having complained of soreness after bowling two overs on Tuesday. A preliminary scan on the affected area had revealed a haematoma, but further assessments were required to determine whether Harmison will be fit to face Hampshire in the Friends Provident Trophy final on Saturday.

Durham batted all day here yesterday, but if they had been in the field, Harmison would not have bowled. This suggests that it would be a big risk for him to be included at Lord’s, although Geoff Cook, the Durham head coach, said that the fast bowler would make every effort to play.

“He hasn’t discounted playing on Saturday because he’s desperately keen to play,” Cook said. “So if we get clearance from the scan and perhaps a bit of treatment, he’ll do everything he possibly can.”

After having a hernia operation on July 17, Harmison was ruled out of England’s three-match Test series against India and his initial recovery period was estimated at four to six weeks. But he made his comeback ahead of schedule for Durham against Sri Lanka A last week, three weeks after the operation. He then played in Durham’s one-day match against Kent on Sunday, after which he drove 350 miles from Canterbury to his Ashington home, arriving at about 2am, before taking the field the next day against Surrey. Cook said that this period of intensive rehabilitation could have caused his new injury.

“Because he’s pushed himself so hard since the hernia operation, it might just be a general workload thing,” Cook said. “There was no specific moment when he felt it, he’s just a bit stiff and sore.”

Because Harmison is so keen to be involved against Hampshire, Cook must make a delicate decision about whether to include a fast bowler who has bowled only 26 overs since his return from injury. “It’s a question of making an honest decision in the best interests of the team,” the head coach said.

Whether or not Harmison plays against Hampshire, his potential absence from the Durham attack could have a crucial bearing on this championship match. The home team had looked in danger of allowing Surrey back in the game yesterday afternoon, when they slipped to 241 for six, a lead of 290 on a pitch that remains true.

Chris Jordan, the 18-year-old seam bowler, took the key wickets of Michael Di Venuto and Shivnarine Chanderpaul, both from miscued pulls to mid-on. Harbhajan Singh always looked dangerous during a 36-over spell from the Finchale End and Surrey looked capable of hauling themselves back into the match.

But then Ottis Gibson, who made a 56-ball half-century, and Ben Harmison, Stephen’s younger brother, joined forces in a seventh-wicket stand of 83 that tilted the match back firmly in Durham’s favour.