The buzz coming through the ever-dubious transfer wires claims that Liverpool are close to signing Glen Johnson from Portsmouth.

Rumors are homing in on a £17m move which includes the £7m Pompey still owe the Reds for Peter Crouch. Johnson is a fine player, full of skill, energy and guile, and his addition to the side could be just the sort of tweaking Rafael Benitez needs to push Liverpool up that final rung on the Premier League ladder.

But even if Benitez can secure Johnson’s services over the likes of Chelsea and Manchester City, he should hold onto Alvaro Arbeloa like a skydiver clinging to his reserve parachute.

Arbeloa’s name arises alongside Andrea Dossena’s as potential transfer window counterweights. The sale of either full-back could be used to soften the financial blow of the swoop for Johnson.

But despite Johnson’s superior quality in the right-back position, Arbeloa is too utile to lose.

Maintaining depth is as important to Liverpool’s title hopes as picking up new quality. While Arbeloa’s best position is right-back, he can also cover as a centre- or full-back if needed. He’d never be a top choice over Carragher, Skrtel, Agger, Aurelio or Insua. But keeping him would insure Liverpool have all their defensive options covered if long-term injury strikes their back line yet again.

Yes, sell Dossena to rase some cash. Even if no other left-back comes to Anfield, Aurelio and Insua can both serve well enough in that position. But the right side has not been so well covered.

Philip Degen struggled with injury last season and as a result, when first choice Arbeloa was out, Jamie Carragher was deployed in the right-back role, and though he’s played that position effectively in the past, his fading speed keeps him from being an ideal backup. Even Javier Mascherano took up the right-back mantle for an outing when the defense was spread thin.

Benitez should be able to get more for Arbeloa than he can for Dossena since the Spaniard made a greater contribution to Liverpool’s fine season than the Italian. Nevertheless, however many pounds can be brought in for Arbeloa’s sale is not worth the piece of mind Liverpool can enjoy knowing he’s there to come off the bench or cover for an injured or resting defender when they need him.

A deeper back line could make all the difference as Liverpool look to put their miserable collection of draws behind them and stamp some dominance on the league.

Arbeloa showed fantastic growth last season. At the year’s beginning, Benitez told us more attack and service would come from the full-backs and Arbeloa answered the call with verve. He created plenty of danger down the side, pushing past defenders to find lanes of service. He even had a cracking goal. A curling left-footer again West Brom in November.

He’s not the best in the world, but he’s been a dependable caretaker in the back, he’s threatening when he gets forward, and he did well enough last year to help keep the Reds in the race longer than they’ve been in a long, long time.

If anything, the real problem will be convincing Arbeloa to stay. Just as Liverpool couldn’t keep Crouch playing in the shadow of Fernando Torres, if Arbeloa loses his starts to Johnson, the lure elsewhere will be strong for the 26 year-old Spanish international. Real Madrid is rumored  to have a renewed interest in their former player. Though, he’d be competing with Sergio Ramos who’s already kept him out of many a Spain start.

But if there’s any chance of Arbeloa staying, Benitez should pursue it. Arvalo’s quality and drive are something Liverpool need to maintain in reserve if they want the depth to challenge for multiple trophies over multiple years. It may take convincing Arbeloa he can be a part of something bigger than regular starts: overturning Liverpool’s two-decade title drought. I know that’s not as alluring as being first-choice elsewhere, but Benitez should still try his best to keep Arvalo Arbeloa with Liverpool. Raise the money through other sales.