Steve Harmison seems to be aware of his fate in Kandy

England captain Michael Vaughan looks unlikely to risk playing strike bowler Steve Harmison in the first Test against Sri Lanka starting on Saturday.

Vaughan said: "Steve is available and he bowled a lot at the nets.

"But it would be a slight risk as we saw him walk off after bowling 10 or 11 overs in the last game."

With Ryan Sidebottom, Matthew Hoggard and James Anderson set to start, the other major decision is whether to play Owais Shah or Ravi Bopara at six.

Interview: England captain Michael Vaughan

Vaughan told BBC Sport: "Everyone's put their hand up and done well at some stage on the tour and in a way everyone warrants a spot in the starting side."

Harmison and Anderson - both having overcome fitness worries - have been competing over one spot.

Durham paceman Harmison was always considered unlikely to play after limping out of England's final warm-up match with a back complaint.

606: DEBATE How do people think the first Test will go? Sri Lanka have just come back from Australia so may not be 100% ready KB_is_back

He was unable to bowl during the last two days in Colombo, after sending down 10.3 overs on Sunday.

But he was given the all-clear to continue training after a scan showed no sign of any fresh damage, and the paceman looked to be firing on full cylinders in Thursday evening's net session.

A healthy growth of grass on the wicket had been shaved off by the time the players arrived for practice on Friday.

That enabled Vaughan to make his final decision about the starting team, though he gave away few clues.

He said: "We are all feeling in a really positive state of mind. It's nice in a way that we're having to make difficult decisions.

"Everyone's fit for selection so that's good.

"It's important that we do get the XI right as we need to get off to a good start to the series.

"Bopara and Shah are both very skilled players, and in these conditions they are very suited to this style of play.

"They both play spin very well. It's a real hard decision as to which gets the number six spot."

Everyone got a good look at the pitch in Kandy on Friday

Lancashire's Anderson damaged his ankle after being hit by a ball while fielding in the final tour match on Sunday, and missed a session on Monday.

But he did return to play on Tuesday.

Though the ankle is now fine, Vaughan and coach Peter Moores will want to be sure the back stiffness he has also been enduring is no longer a factor.

Speaking earlier this week, Harmison admitted he was frustrated by his sore back.

"I can't get rid of an injury without another one cropping up," he said.

"I need to spend some time on the park, and if I do that and bowl properly I feel I'm as good as anyone in England."

Sri Lanka have released opening batsman Upul Tharanga, leaving a squad of 13.

Captain Mahela Jayawardene said of Tharanga: "He had a very lean period then scored some useful runs in the last few games, which is great for him, but he will have to be a bit more patient."

Veteran Sanath Jayasuriya is certain to play, but will not necessarily open if Sri Lanka ask Jehan Mubarak and Michael Vandort to face the new ball.

The only other selection decision for Sri Lanka to make is whether to include Dilhara Fernando in a three-pronged pace attack or include leg-spinner Malinga Bandara.

It's very tough cricket over here but very rewarding when you win Michael Vaughan

Muttiah Muralitharan is targeting the five wickets he needs to overhaul Shane Warne's 708 career tally, while Chaminda Vaas will be earning his 100th Test cap.

Vaughan said: "Murali is always going to be a threat.

"Any team who have come to Sri Lanka and been successful have played Murali well and we have to make him bowl a lot of overs.

"It's very tough cricket over here but very rewarding when you win.

"I was here when we won in 2001. We lost 1-0 last time but fought very hard in the first two matches."

Vaas, 33, said on Friday he would give himself another 12 months of Test cricket before retiring from the game.

Extra security has also been given to the hotels where the players are staying, according to police sources.

On Wednesday twin bomb blasts, attributed by police to the Tamil Tigers terrorist organisation, killed 19 people and left 45 injured in Colombo.

England (from): Michael Vaughan (capt), Alastair Cook, Ian Bell, Kevin Pietersen, Paul Collingwood, Owais Shah, Ravi Bopara, Matt Prior (wkt), Steve Harmison, Ryan Sidebottom, Matthew Hoggard, Monty Panesar, James Anderson.